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bigstud/toiletset: re: your lies, re: images...
my post from yahoo...
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http://messages.finance.yahoo.com/Stocks_%28A_to_Z%29/Stocks_I/threadview?m=tm&bn=34920&tid=32732&mid=32732&tof=2&frt=1
the cardiologist and dean met on middle ground, listen to the 12/9/09 conference call at time stamp 22:30.
dean did not state that the images were subpar... around time stamp 25:15 he stated that he could accommodate peers (and hey sexyfirelady, key word here is peers), and would send him or his colleagues some images with some compression to see from a DICOM sense...
now, i suppose you could tell me some of the finer intricacies of DICOM... answer: i already know, but i would love to hear your lies on this...
keep 'em going your getting even more ridiculous/desperate...
now, keep reading:
the only thing he has stated in the past regarding some sort of inability to intrepret is the facts surrounding the quality assurance (QA) images, as those ARE NOT clinical and most clinicians would not understand them...
however, to those inclined to understand the world of radiophysics, high/low contrast images are some of the prettiest pictures around.
now, keep reading: this is where it gets fun:
in reply to the question beginning at time stamp 41:00 he goes on to say (without hesitation, or without any sorta sense of becoming flustered) that the DViS at RSNA was not the current development system and that the 3d images taken to RSNA were not of the same res (i.e., resolution) than what they are working with now - or display now - and what the FDA has seen... and obviously you can't display your product live at the show...
NOTE: this sounds no different than the c-arm exhibitors i've visited at conferences.
finally:
i think that same caller is talking about you, as he goes on to talk about things being taken out of context and subsequent rumor-mills on message boards.
jony10: in re: to your question ...
the x-ray beam is emitted from the source to the detector plate... because both spin on the same track the x-ray photons always strike the detector...
3rd generation CT scanners are the most prevalent...
often they might keep heavily used scanners spinning at a designated speed, the ones at sites or settings that get a lot of foot traffic, and just ramp up and then obviously emit when examining/when necessary.
here's 3rd generation CT spinning up to max speed...
alexdhcfx... please note:
the message boards have mixed and mashed the verbage quite a lot...
here's my post from november 1st on this where dean uses the word i-n-t-e-n-d-e-d use.
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hi all --- i'm correct ... see inside ... 1-Nov-09 07:59 am below is the link to the last conference...
sexylady has gone ape nuts about prior cc's not mentioning indicated use...
i have patiently tried to explain that yes the CEO has mentioned "indicated use." it has been an ongoing thing during the review process as the FDA has tried to better understand this paradigm shif in fluoroscopic guidance that dean has given them to review.
nevertheless, read my other thread for what the DViS is and should be all about regarding that.
sexylady has stated that there is something strange going on... all of a sudden like...
i've stated otherwise...
here is the link:
http://www.imaging3.com/State_of_Company...
listen to the question beginning at 10:24
dean then states that he answered those questions in the last cc (i.e., prior to 9/23/09). however, in and of the answer to this question is the term i-n-t-e-n-d-e-d at the 10:51 time point...
intended use...
then the CEO states, "i don't control the FDA."
fast forward...the FDA wants CLARIFICATION not revision...
http://messages.finance.yahoo.com/Stocks_%28A_to_Z%29/Stocks_I/threadview?m=tm&bn=34920&tid=11611&mid=11611&tof=-1&rt=1&frt=2&off=1
bart ~ on off-label...
dean mentions this in the cc of 12/9/09... wherein he is discussing rewording the intended use statements to more generic statements. wherein he goes on to say that, as par for the course, so to say, it is typical to finish such statements with some sort of clause that physicians/providers may use as they see fit for the medical case. the point he is trying to make on this is discusssed in the article on radiology and the history of and process for regulating and bringing medical devices to market...per this article.
http://investorshub.advfn.com/boards/read_msg.aspx?message_id=44706307
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and i sorta describe it here because i describe what i don't think the label will offer...
e.g., i don't see it being used for CT angiography...
http://investorshub.advfn.com/boards/read_msg.aspx?message_id=44118234
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now, for a more direct answer to your question...
anything re: mammo ~ would need to be applied/submitted for... i.e., no off-label use for that there...
anything re: weight-bearing CT scanning ~ would not be possible in current physical configurations as we know it... in other words, you will need to have a gantry which comes of from the floor for example to surround the region of interest, think hula hoop or something.
anything re: radiation therapy planning ~ this can be a possible off-label use in my opinion.
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in general, fluoroscopes do not provide the details of radiographic equipment... let me be more precise... radiologists would not want to go on record diagnosing a stress fracture of a finger/hand/wrist or of the say, 5th metatarsal of the foot based on a fluoro-image... good ole plain films will provide much better recorded detail. moreover, such fractures are sometimes occult fractures and will require nuclear medicine SPECT scanning to diagnose.
in general, fluoroscopes [more specific mobile fluoroscopes] are like any other viewing scope, i.e., think endoscopic surgery, or arthroscopic surgery, where the camera is put into the area. a fluoroscope can be used anywhere they want to see what they are doing... and how often do surgeons, interventionalists need to see what they are doing... answer: well, i wouldn't want one who keeps his eyes closed performing anything on me.
that said, for an example of an instance where no camera is necessary, as follows: to create a pocket to put in say an implantable generator (neuromodulator device, etc.) and then suture it in and close the site. however, i can't think of a situation where fluoro would not be necessary for the rest of these types of procedures. now, when speaking about electrophysiology cases, such as pacers, etc.... the fluoro-suite is most often some sort of fixed c-arm fluoro system. although, such departments typically have a one or two mobile systems on the floor (at least the ones i've been too).
but you get my point...
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thinking outloud, i think that the cone-beam CT feature of the DViS will have intra-operative uses/indications...as i mentioned in my "short-list of procedures" post.
if an ER wants to use it too, then in my opinion go right ahead...as long as the ER has the space/adequate footpring, i can't see any physical/logistical difficulties with that... consider the LODOX Statscan device i've mentioned before... the concept there is for trauma... in the ER setting... the Statscan is a radiography device... the point here is that the model for having some sorta radiation emitting device in an ER already exists. moreover...the Statscan is fixed unit. One ER system that i think of first when i think of the Statscan is the Shock Trauma system throughout Maryland and surrounding areas... then, think moble x-ray in the ER, that model exists obviously.
however, i believe there is a technology limit (at this time) to do brain CT scanning with existing cone-beam technology... this statement is based on my understanding of the literature...although i must preface that that literature i've read seems to have an affinity for the CereTom portable CT scanner...albeit that is a multidetector or multislice CT.
re: post #7399 ~ i don't think you know what you're talking about.
okay mr. sano...short-list of procedures...
to quote dean first, labeling was put into a generic context...
1.// thus, orthopaedic encompasses simple orthopaedics to simple sports medicine...
remember ortho means straight, and in fluoroscopy and radiography when you evaluate you must obtain 2 perpendicular views: in order to judge the three D's -- Depth, Direction, Depth. and, no, i didn't misphrase that... you obtain this via orthogonal (right angle) views...
so, orthopaedics represents a plethora...given the realtime 3D nature only available via the DViS, together with the icing on the cake, sectional viewing by cone-beam CT.
NEUOROSURGERY:
let's simply consider fusion surgeries of the cervical or lumbar spine... and in particular, pedicle screw placements... Depth, Direction, and Depth.
or let's consider microdiscectomies.
IMPORTANTLY: THE DViS GANTRY IS LARGER SIZED COMPARED TO CURRENT CT TECHNOLOGY, THUS A WELCOMING/FRIENDLY ENVIRONMENT FOR THE SURGEON/INTERVENTIONALIST.
NOTE: Depth, Direction, and Depth, also apply to needle placement as well as to any surgical too placement, but less important in the latter case if the surgeon is incorporating endoscopic viewing or is looking directly at the target through open tissues.
2.// but, lets name some other names.
myleograms.
CT myelograms.
discograms (diagnostically speaking) --- as well as the post-disco CT scan which follows --- this is the evaluation to identify suspected deranged intervertebral discs, NOT ABLE TO BE IDENTIFIED VIA MRI. in and of itself, the discogram procedure is absolutely necessary to place the contrast media into the targeted disc(s) for sectional viewing by CT, although their is more to the procedure to provide more info for the neurosurgeon. thus, discograms can help neurosurgeons by the evaluation of identifying said disc(s), and probabilities for the need for surgical intervention and thus, serve as a "planning procedures," to identify were to invasively proceed if surgery is thought to benefit the patient.
perhaps, one machine for both exams...especially for free-standing physician centers.
intradiscal injections --- same procedure as above, but used as a non-surgical intervention. no CT scan necessary here.
3.// and other names.
vertebroplasty.
kyphoplasty.
--- these are interventions which stabilize compression fractures of the vertebral bodies, for instance, T12.
there's a neurosurgeon that uses 2 mobile single arm multidirectional fluoro c-arms at this time, i.e., basic c-arms... remember the biplanar c-arms didn't really catch on.
INTERVENTIONAL PAIN
facet injections...
medial branch blocks...and radiofrequency ablations of the medial brach...
transforaminal epidurals...
interlaminal epidurals...
caudal epidurals...
sympatethic nerve blocks...
- hypogastric variety.
- traditional variety.
- stellate variety.
all above a short list for entirety of the spine, lumbar, thoracic, cervical.
sacroilliac injections.
pudendal nerve injections.
4.// let's name some general operating room surgeries, which currently require fluoroscopic-guidance.
brachytherapy --- think prostate seed placements.
cholecystectomy --- removal of gall bladder.
intra-ureter and kidney evaluations.
ENT surgeries --- ears, nose, throat.
5.// ct = cardiac-thoracic surgeries...
to quote the thoughts of the cardiologist on the 12/9/09 cc.
- triple A repair -- aortic abdominal aneurysm repair.
- thoracic aneurysm repair.
- abdominal aneurysm repair.
thoracotomy procedures...
- thoracotomy with wedge resection.
- thoracotomy with lobectomy.
- thoracotomy with pneumonectomy.
6.// possibly central venous access port placement procedures...
THESE ABOVE IS THE SHORT LIST: OBVIOUSLY, I'M NOT GONNA BE ABLE TO WRIGHT DOWN EVERYTHING HERE (I.E., SPEND ALL DAY DOING THAT).
down the road, i see benefit for cone-beam CT and radiotherapy applications... or radiotherapy planning...
down the road, i see benefit for weight-bearing cone-beam CT applications of the weight bearing joints...which would represent a first, and a leap from weight bearing plain films...to further assist our orthopaedic colleagues...
joe et al., regarding medical devices in radiology, please allow me to repost this link, or better yet post the article and emphasize with bold print some interesting parts...
Regulation of Medical Devices in Radiology: Current Standards and Future Opportunities1
John J. Smith, MD, JD
+ Author Affiliations
1From the Department of Radiology, Massachusetts General Hospital, 55 Fruit St, Boston, MA 02114; Harvard Medical School, Boston; and the Center for Integration of Medicine and Innovative Technology, Boston. Received August 31, 1999; revision requested October 21; revision received November 19; accepted December 17. Supported in part by a grant from the Center for Innovative Minimally Invasive Therapy, a nonprofit consortium consisting of Massachusetts General Hospital, Brigham and Women’s Hospital, Massachusetts Institute of Technology, and Draper Laboratory. Address correspondence to the author (e-mail: smith.john@mgh.harvard.edu).
Abstract
Today’s radiology community depends heavily on cutting-edge diagnostic and therapeutic medical devices to serve patients. These products are regulated by the U.S. Food and Drug Administration (FDA) under a system that grants marketing approval for only those indications for which the safety and effectiveness have been established. Although this complex system is the result of a societal decision to ensure device safety and effectiveness, it has the potential to delay product marketing and impede innovation. Medical device regulation recently has undergone major changes with the enactment of the Food and Drug Administration Modernization Act of 1997 (FDAMA), legislation that is intended to increase system efficiency while retaining the requirement of safety and effectiveness. However, many of the envisioned improvements cannot occur without cooperative interaction between stakeholders in the device development process, including the FDA and the clinical medicine community. The radiology field must continue to build on its strong history of productive dialogue with the FDA to transform the legislative vision of FDAMA into regulatory reality. Such action will ensure timely access to the new device technologies that are necessary for the growth of our specialty and the effective care of our patients.
[INTRODUCTION]
Modern radiology is heavily dependent on the use of state-of-the-art diagnostic and therapeutic devices; thus, timely federal regulatory approval of new devices is crucial to the availability of innovative technology to effectively serve our patients and build our specialty. This regulatory scheme recently experienced major changes with the enactment of the Food and Drug Administration Modernization Act of 1997 (FDAMA) (1). FDAMA, in addition to altering many existing regulatory provisions, has fostered an atmosphere of cooperation and responsiveness on the part of the U.S. Food and Drug Administration (FDA) to address the concerns of clinical medicine and industrial communities. Despite these positive developments, there remain elements of the FDA’s new device evaluation process that pose considerable practical impediments to bringing new technologies to market. It is incumbent on the radiology community to build on its long history of productive interaction with the FDA and use the opportunity for collaboration presented by FDAMA to facilitate positive change in the regulation of the devices that are so important to our patients and the future of our specialty.
HISTORY OF MEDICAL DEVICE REGULATION
Device Regulation before 1976
Comprehensive medical device regulation is a relatively new addition to federal regulations of medical products. Although drugs have been federally regulated since the passage of the 1906 Food and Drugs Act (2), devices were not included in the regulatory framework until the passage of the Food, Drug, and Cosmetic Act of 1938 (FDCA) (3). Even then, the authority to regulate the comparatively simple devices of that time was quite limited—that is, confined to challenging the sale of products believed to be “adulterated” (ie, unsanitary or unsafe) or “misbranded” (ie, bearing false or misleading claims). It is notable that manufacturers were not required to establish the safety and effectiveness of their products prior to marketing them.
Device regulation remained relatively unchanged until the 1960s, when an explosion in technology ushered in a variety of new products, some of which posed substantial potential risks to patients. Facing a possible public health problem and lacking regulatory authority to evaluate medical devices prior to marketing, the FDA crafted a controversial stopgap solution. The FDCA, as modified by the drug amendments of 1962, contained a premarket approval process for new drugs in which a manufacturer was required to establish the safety and effectiveness of a given product before marketing it (4). Building on this drug-based regulatory authority, the FDA classified as drugs a number of products that were arguably devices and applied the premarket approval requirements. This policy was frequently upheld by the courts (5,6). However, it was difficult to apply on a large scale, and an active search for a more structured approach was begun.
Congress acted to regulate medical devices that emitted radiation by passing the Radiation Control for Health and Safety Act of 1968, which was designed to protect the public from excessive radiation exposure (7). This legislation, which applied to any radiation-producing product, including consumer items and industrial tools, gave the FDA the power to develop and enforce performance standards for diagnostic x-ray equipment, medical lasers, and ultrasonographic (US) therapy equipment.
The need for more comprehensive medical device regulation led to the formation of the Cooper Committee, a federal committee charged with exploring possible regulatory solutions (8). In its 1970 report, this committee observed the wide range of risks and complexities of medical devices and concluded that these products should not be regulated with a single approach, as was done with drugs. The report recommended a new tiered regulatory system, in which devices that posed a higher perceived risk to patients would be subject to more demanding requirements than those that posed a lower level of risk.
Medical Device Amendments of 1976
The Medical Device Amendments of 1976 (MDA) were intended to ensure that devices are safe and effective for the indication(s) for which they are legally marketed (9). The MDA, following the Cooper Committee’s recommendations, mandated a risk-based three-tiered system for device regulation that is still in use today. Under this legislation, all medical devices legally marketed prior to the implementation of the MDA on May 28, 1976, are placed into one of three classes with the assistance of expert advisory committees.
Class I devices are those that are not purported or represented to be for a use that is of substantial importance in preventing impairment of human health and that do not present a potentially unreasonable risk of patient injury. Devices in this category are not individually regulated, but they are subject to “general controls”—that is, regulations designed to ensure the safe manufacturing and correct labeling of all medical devices. As such, general controls apply also to class II and class III devices. Examples of class I products are lead gonadal shields and x-ray grids.
Class II devices present a greater risk of harm than do class I devices and may be subject to additional regulation in the form of “special controls,” which are applied to specific device types. As with class I products, there is no individual regulation of these devices. Examples of class II devices include higher technology products that do not by themselves maintain life, such as diagnostic angiographic catheters and many diagnostic devices, including computed tomography (CT), magnetic resonance (MR), and US imaging units.
Class III products include high-risk devices that are “represented to be for use in supporting or sustaining human life or for a use which is of substantial importance in preventing impairment of human health,” or that “presents a potential unreasonable risk of illness or injury” (9). All products in this class are individually regulated and subject to a premarket approval process in which the manufacturer is required to establish the safety and effectiveness of the device before marketing it. Devices in this category include vascular stents and detachable endovascular coils.
The MDA further divides devices into those that were legally marketed before implementation of the legislation on May 28, 1976—pre-1976 devices—and those that were marketed after that date—post-1976 devices. Pre-1976 devices can continue to be legally marketed without additional approval from the FDA, although class III products are subject to future FDA demands for safety and effectiveness data.
New post-1976 devices are evaluated before being marketed under the MDA premarket notification requirement, which is commonly known by its FDCA section number, 510(k). Section 510(k), as originally enacted, required manufacturers to notify the FDA of their intention to market essentially any new product. If the FDA determined that the new device was “substantially equivalent” to a pre-1976 product, the product was placed in the class of its “predicate” product, which is a term used by the agency to denote a legally marketed existing product to which a new device may be substantially equivalent. Citations in the peer-reviewed literature and the expert opinion of physicians played an important role in the determination of substantial equivalence. With substantial equivalency established, the new device could then be marketed immediately, under the existing regulations imposed on the predicate product. New products introduced after 1976 that lacked predicates were automatically placed in the class III category and subject to a premarket approval process that generally required clinical trials.
Section 510(k) did not include a definition of “substantial equivalence,” so the FDA was left to define the term. Most commentators agree that the FDA focused on the comparability in operation and clinical use between the two devices when determining substantial equivalence (10). The agency usually did not require clinical trials to establish comparability and declare a product substantially equivalent. The agency further broadened section 510(k) by introducing “piggybacking”—that is, allowing post-1976 devices that were judged to be substantially equivalent to pre-1976 products to serve as predicate devices (10). This policy effectively permitted evolutionary change in predicate devices without subjecting incrementally changed products to the more demanding premarket approval process.
Helical CT is an example of device evolution that was permitted under the FDA definition of substantially equivalent (11). Developed in the late 1960s and legally marketed prior to 1976, conventional CT scanners were considered to be pre-1976 products and placed in the class II category. Helical scanning represented a significant change in the method by which images were obtained, although the overall operation and use of the technology were very similar to those of the existing products. The FDA focused on these similarities to determine that the safety and effectiveness of helical CT paralleled those of conventional CT. After evaluating laboratory and clinical data, the FDA determined that helical CT was substantially equivalent to existing CT technology and permitted the marketing of the helical device as a class II product.
Device Regulation between 1976 and 1997
The MDA represented a major expansion in the regulation of medical devices and imposed a considerable new administrative burden on the FDA. Although many of the regulatory mechanisms in the MDA were patterned after established drug regulatory tools, their application to devices raised new issues. For example, the premarket approval process developed for drugs was not directly transferable to devices. Adding to the problem was the challenge of developing a comprehensive device regulatory process where a relatively limited program had been in place—an exercise that strained agency resources. During the next 2 decades, the FDA and Congress continued to face challenges in fully implementing the vision of the MDA.
Congress revisited medical device regulation in 1990 with the Safe Medical Devices Act of 1990 (12). This legislation was intended primarily to strengthen the FDA’s authority to monitor marketed products (11,13). The act also required the FDA to affirm a device’s substantial equivalence before marketing and recognized the agency’s authority to request clinical data to establish substantial equivalence for devices that differed in technology or design from the claimed predicate product. Two years later, Congress enacted the Medical Device Amendments of 1992 (14). This legislation was designed to clarify the Safe Medical Devices Act of 1990 and largely technical in nature; the regulatory framework of the initial legislation was essentially unaltered (15).
Before the early to middle 1990s, the device regulatory system established by the MDA, as amended in 1990 and 1992, functioned differently from the rigid single-path regulatory framework in place for new drugs (10). This was not surprising for the lower risk class I and II products, which were generally approved with 510(k) applications and not subject to premarket approval system regulations. However, even the relatively high-risk class III products usually were not subject to the same rigorous scrutiny applied to drugs, which ordinarily involved three discrete phases of clinical testing to establish safety and effectiveness. In addition, device trials infrequently featured the double-blind placebo-controlled study design that was generally acknowledged to constitute the “gold standard” for new drug clinical testing.
FDA evaluation of devices became a national issue in the early 1990s, however, when safety concerns regarding silicone breast implants received widespread publicity. These pre-1976 devices and their substantially equivalent post-1976 “cousins” were legally marketed under the pre-1976 class III provisions and had not been formally evaluated for safety and effectiveness. Fueled by considerable media attention, the controversy quickly spread from a focus on implants to an investigation of the entire device regulatory system—in particular, the science underlying the evaluation of safety and effectiveness.
The FDA responded to the controversy by organizing the Committee for Clinical Review to study device evaluation; this group consisted almost exclusively of FDA employees responsible for drug evaluation (16). In its final report, the “Temple committee,” as it became known, concluded that the fundamental principles underlying the evaluation of any therapeutic intervention, whether drug or device, should be the same. Furthermore, the committee did not recognize any distinction between studies designed to demonstrate substantial equivalence under section 510(k) and those intended to show safety and effectiveness in the premarket approval process. These findings combined had the potential to alter the FDA’s basic approach to medical device evaluation and substantially increase the regulatory burden of 510(k) requirements for substantial equivalence, which were traditionally less demanding than the premarket approval applications. Then FDA Commissioner David Kessler, MD, endorsed the report and promised to ensure the implementation of its recommendations (10).
In the aftermath of the silicone implant controversy and the Temple report, the FDA began to introduce changes that some commentators contend blurred the distinction between evaluation of new devices and evaluation of new drugs (10). Regardless of the underlying philosophy, there was no doubt that FDA scrutiny of devices had increased and with it, the amount of data and time required to bring new products to market. Delays in securing marketing approval resulted in substantial criticism from physicians, the medical device industry, and Congress (15,17). The 1994 Congressional elections, which established Republican majorities in both the Senate and the House of Representatives, set the stage for action directed at repairing what some contended had become an unnecessarily burdensome device regulatory system. The FDA responded to this pressure by instituting a “reengineering” effort, under which various initiatives were undertaken to improve regulatory efficiency. However, this program did not fully satisfy FDA critics, who continued to push for new legislation.
Food and Drug Administration Modernization Act of 1997
Efforts to reform the device regulatory system culminated in FDAMA, which was signed into law on November 21, 1997 (1). This legislation does not alter the statutory requirement that devices be safe and effective for their approved indications. Rather, its goal is to improve regulatory efficiency by building on administrative reforms already underway at the FDA and ensuring greater agency accountability through a plan for compliance (18,19). As part of this process, the aim of FDAMA is to increase cooperation and communication between the FDA and those affected by the regulatory system, such as physicians and the industrial community. Specific FDAMA provisions address a number of issues, such as focusing FDA resources on high-risk devices, improving the efficiency of device evaluation, speeding up the introduction of important new technologies, and addressing the off-label use—that is, use for indications other than those on the FDA-approved labeling or package insert—of approved devices.
Focusing on high-risk devices.
—Under FDAMA, the FDA focuses its resources on high-risk devices through various provisions. Section 206 exempts the majority of class I and many class II products from premarket FDA notification under section 510(k) and reserves the process for higher risk products. Under section 210, parties outside of the FDA may be accredited to review class I and lower risk class II device premarket notification applications, so that the FDA is able to concentrate on higher risk class II and high-risk class III products. Sections 207 and 416 contain provisions to reclassify devices, in particular, genuinely new products (with no predicate devices) that are automatically considered as class III devices. Although it remains to be seen how the latter provisions will be applied, they presumably will be used to expeditiously move lower risk products from class III designation, which requires so much agency attention.
Improving the efficiency of device evaluation.
—A variety of FDAMA provisions function to improve the overall efficiency of the device evaluation process. Section 205 requires the FDA to consider the “least burdensome” means of evaluating effectiveness that would have a reasonable likelihood of resulting in approval for both 510(k) and premarket approval applications. Section 201 allows the FDA to use data from previous clinical trials to support the applications of subsequent devices under certain circumstances. For those devices that necessitate clinical trials, section 217 specifically states that “reasonable assurance of effectiveness” may be demonstrated by the results of only one well-controlled clinical investigation, where appropriate (1). Section 404 mandates that to address significant scientific controversies that develop between the FDA and those it regulates, the agency is required to establish a dispute resolution process. Finally, section 204 explicitly incorporates standards into the evaluation process; this provision allows the FDA to recognize consensus standards and use them in product reviews.
Several provisions of FDAMA focus on specific types of applications. For example, section 209 establishes a 90-day time frame during which the agency must make an initial classification decision on 510(k) submissions for devices that have not been previously classified. This provision is clearly directed at the substantial delays in processing 510(k) applications that arose in the middle 1990s.
The concept of a binding meeting was introduced for products that are subject to premarket FDA approval and certain other products. Section 201 allows a sponsor of a class III, or implantable device, to request an “agreement” meeting, during which the FDA and the sponsor agree to a binding investigational plan. Unilateral FDA action to change the agreement is allowed only when a substantial scientific issue that is essential to determining the given product’s safety and effectiveness subsequently develops. A binding meeting to agree on the type of evidence needed to support premarket approval of a device, known as a “determination” meeting, is provided for in section 205. Like section 201, the results of this meeting commit the FDA to a course of action, in the absence of a subsequent determination that the agreement is contrary to public health.
Section 205 authorizes the FDA to use postmarket controls in evaluating either a 510(k) or premarket approval application. This provision presumably allows the agency to expedite marketing approval by requiring some type of postmarket evaluation process.
Expedited introduction of important new technologies.
—Section 202 provides for a priority review of certain devices. These include devices (a) that represent breakthrough technologies, (b) for which no approved alternatives exist, (c) that offer substantial advantages over approved therapies, and/or (d) for which availability is in the best interest of patients. In addition, section 402 allows expanded patient access to investigational therapies and diagnostic techniques under specified conditions.
Off-label use of medical devices.
—The FDCA regulates the marketing of medical devices but not their use by licensed physicians. Devices and other medical products are commonly used for indications other than those contained in their FDA-approved labeling or package insert, a practice known as off-label use. An example is deploying a stent that is approved for use in the iliac arteries in the iliac veins. For years, the FDA has acknowledged the right of health care providers to engage in such use under the “practice of medicine doctrine”; however, the concept was never formalized in the statute or implementing regulations (20–23).
Section 214 of FDAMA explicitly acknowledges the practice of medicine doctrine in the context of medical devices. It prohibits the FDA from interfering with the authority of a health care practitioner to prescribe or administer any legally marketed device for any condition or disease within a legitimate practitioner-patient relationship. This provision appears to codify the long-standing FDA deference to off-label use; this is supported by an explicit disclaimer stating that the section does nothing to limit existing FDA regulatory authority.
Section 401 addresses the problematic issue of manufacturer distribution of information with off-label use; such distribution was substantially limited by the FDA prior to FDAMA (24,25). The new provision allows such distribution, but only when a manufacturer agrees to submit a supplemental application for that off-label use or the FDA explicitly waives the requirement. Although the FDA’s regulations to implement these provisions were the subject of an initially successful legal challenge, a subsequent appellate decision reversed the Federal district court and apparently upheld the legality of the provisions (26).
CURRENT MEDICAL DEVICE REGULATION SYSTEM
Regulatory Treatment of New Devices
The decades-long process of establishing a comprehensive device regulatory system that began with the MDA has culminated in a complex system designed to ensure that medical devices are safe and effective for their FDA-approved indication(s). It is a system that focuses on the marketing of products, not on their ultimate use by health care professionals. To understand the operation and inherent problems of this system, it is useful to trace how a new medical device secures FDA marketing approval for a specific clinical application.
Premarket notification–exempt class I and class II devices may be legally marketed without first informing the FDA. These products must be in compliance with general controls, which are a collection of agency regulations that are applicable to all medical devices and designed to ensure that products are safely manufactured and correctly labeled (27). General controls include prohibitions against misbranding and adulteration, as well as requirements for reporting and record keeping. Manufacturers must register with the FDA, comply with labeling requirements, and design and produce devices by using “good manufacturing practices”—that is, requirements designed to maintain quality in the manufacturing process. Class II products may be subject to additional regulation in the form of special controls. Marketing of a gonadal shield, an exempt class I product, illustrates the operation of this system for all premarket notification–exempt class I and class II devices. A registered device manufacturer seeking to market this product needs only to manufacturer and label the shield in accordance with applicable general controls before distributing it. Sales may then commence without formal notification to the FDA.
Nonexempt class I and class II, class III, and all genuinely new products are subject to the premarket notification provisions of section 510(k). Manufacturers of these products must submit applications describing the indication(s) and use(s) of the device, as well as data to support a claim of substantial equivalence to a predicate device. These data generally do not involve clinical trials, but such trials may be required. Should the FDA determine that the new device is substantially equivalent, it is classed with its predicate and becomes subject to identical regulatory requirements. This is relatively straightforward when the predicate device is in class I or class II, because these products are not individually regulated and a manufacturer needs only to comply with the existing regulations that are applicable to the product. For example, the manufacturer of a new CT scanner typically has to submit engineering specifications on the performance and safety of the unit as part of a 510(k) application to support the contention that the new device is substantially equivalent to previous CT scanners. Once this equivalence has been established, the new unit may be marketed and is subject to existing regulations applicable to CT scanners.
Products with a class III designation are more complicated. If the predicate is a pre-1976 product for which the FDA has not requested premarket approval data, the substantially equivalent new device may be legally marketed until the agency requests such data and either the manufacturer fails to provide it or the supplied data do not demonstrate reasonable safety and effectiveness. Should the predicate have been subject to the premarket approval process, the manufacturer of the new product must generally submit data supporting its safety and effectiveness, because data from previous premarket approval submissions are considered proprietary.
New medical devices without a predicate are automatically placed in the class III category. It is possible to reclassify such a product by means of petition by either the manufacturer or the FDA on its own initiative, providing that there are data indicating that regulation of the device as a class I or II product would be sufficient to reasonably ensure safety and effectiveness. An example of a reclassified product is the standard MR imaging unit, a post-1976 device that was originally designated a class III product and marketed by using the premarket approval process. The modality was subsequently down classified to class II after the results of several years of studies demonstrated that it did not pose a substantial risk to patients (10). In the absence of such data or when a device meets the FDCA definition of a class III product (ie, “represented to be for use in supporting or sustaining human life or for a use which is of substantial importance in preventing impairment of human health” or that “presents a potential unreasonable risk of illness or injury” [9]), it remains in class III and is subject to the premarket approval process.
Premarket approval of post-1976 class III devices necessitates demonstration of reasonable safety and effectiveness before marketing. A similar standard applies to pre-1976 class III products for which the FDA has requested data; however, these products generally may be marketed while data are being gathered. Establishing a device’s safety and effectiveness often necessitates human clinical data, the type of which is determined on a device-specific basis. These requirements may be satisfied by using a single study, where appropriate. An experimental design is conceived by the device’s sponsor, usually in consultation with expert physicians and scientists, and approved by the FDA and the individual investigational review boards at the participating institutions. The device is distributed to the clinical centers that are conducting the trial(s) under an investigational device exemption, which allows interstate distribution of the device exclusively for use in the trial. The resultant data are then analyzed by the FDA to determine whether safety and effectiveness have been established.
The overall time frame for determination of substantial equivalence under section 510(k) or marketing approval under the premarket approval process is variable and heavily dependent on the product at issue. In most situations, and particularly those involving clinical data, the FDA encourages early sponsor contact with the agency to ensure that the data collected meet statutory requirements. In general, 510(k) applications for which no clinical data are required receive relatively rapid FDA determinations, whereas 510(k) or premarket approval applications that necessitate clinical data take substantially longer. As of the fiscal year 1999, the average FDA review time for 510(k) applications was 74 days, with a comparable figure for premarket approval applications, 12 months (28). It is notable that these times do not include the sponsor time spent gathering data, preparing the application, and addressing FDA requests for additional data.
Data collection requirements may not end with marketing approval for high-risk class II and class III products, because section 522 of FDAMA allows the FDA to require postmarket surveillance. The agency has recognized the need to collect such data when there are important unanswered questions and a postmarket approach is practical (29). Such approaches may include detailed review of complaint history and scientific literature, nonclinical testing, follow-up of a defined patient sample, use of existing secondary data sets, use of registries, and/or even follow-up clinical trials. The requirements for and type of postmarket surveillance are device-specific and determined at the time of marketing approval.
Importance of FDA Marketing Approval
FDA approval of a new medical device allows a manufacturer to commercially distribute and market a product for the application(s) included on the approved labeling or package insert. However, the practical implications of FDA approval for a given application reach beyond the obvious benefits.
Since 1986, the Health Care Financing Administration (HCFA), the federal agency that oversees the Medicare program, has maintained a general policy that reimbursement for procedures and services that involve the use of medical devices will be provided only if the device is FDA approved for the indication in question (30). This policy, which reflects a statutory prohibition against paying for experimental therapies, has been followed by many other third-party payers. Over the years, this general prohibition has been gradually relaxed. Initially, an FDA-HCFA agreement allowed for reimbursement of devices that are undergoing clinical testing under certain limited circumstances (31). In 2000, President Clinton directed HCFA to provide reimbursement for “routine” medical care associated with clinical trials, although coverage for the experimental devices themselves is subject to the existing FDA-HCFA agreement (32). Still, in practical terms, off-label and experimental use of medical devices creates considerable reimbursement questions for providers and institutions.
FDA marketing approval has been used by plaintiff attorneys as a de facto medical standard of care. Specifically, it has been maintained that the use of a medical device for an indication that lacks FDA approval is experimental. Although this contention ignores the traditional legal distinction between the medical standard of care established by physicians and an FDA regulatory decision based on statutory criteria, it has appeared in a number of lawsuits (33–37). The result has been heightened awareness by physicians, administrators, and risk managers of the potential legal pitfalls of off-label use. There have been anecdotal reports of such use being restricted or prohibited by hospital lawyers or risk managers (JJ Smith, MD, JD, ME Jensen, MD, JE Dion, MD, unpublished data, 1996). Although the effects of potential legal liability linked to off-label use are difficult to quantify, there is little doubt that they have limited off-label use of medical devices.
DISCUSSION
Inherent Problems Facing the Device Regulatory System
FDA regulation of medical devices is a complex indication-specific approval system designed to ensure the safety and effectiveness of products for their marketed indication(s). Although this system reflects a societal decision to ensure the safety and therapeutic benefit of medical products, it also creates an environment with the potential to stifle technical innovation. Potential obstacles to such innovation include the indication-specific nature of marketing approval, the considerable latitude given the FDA in evaluating new products, and the treatment of genuinely new medical devices.
Indication-specific device approval is an inherent component of any regulatory system designed to ensure therapeutic effectiveness. However, providing data, particularly clinical information, to support marketing approval for a clinical indication is time-consuming and costly. Furthermore, the practice of medical doctrine allows physicians to routinely use devices off label. The result is an environment in which manufacturers may lack the incentive to secure FDA approval for additional clinical indications beyond the single indication necessary to gain market access.
Further complicating this environment is the complex, somewhat restrictive FDA policy governing manufacturer dissemination of information on off-label use. To avoid potential regulatory violations, most companies have elected a cautious approach. Distribution of materials, usually journal articles, on off-label use typically occurs only when such information is explicitly requested by a health care provider. Even then, the provided literature generally includes an explicit disclaimer that the use described is not FDA approved and that the company does not support or recommend such use. Industries are very reluctant to provide additional information or product support for off-label use, particularly from their sales force, owing to fear of being seen as a promoter of the nonapproved use.
Given that manufacturers are often in the best position to inform practitioners of the various uses of their products and that the current regulatory climate substantially limits the dissemination of information for nonapproved indications, state-of-the-art therapies based on off-label use of existing products may be slow to diffuse into widespread clinical practice. In addition, the lack of FDA approval for a specific clinical application may complicate efforts to obtain third-party reimbursement or raise risk management questions that may lead to limited off-label use.
The FDCA is vague in its requirements for new device approval: It states only that there must be “reasonable assurance” of safety and effectiveness. The day-to-day definition of this standard is determined by the FDA; this is a prudent decision in an environment where continuing scientific advancement can rapidly change the methods by which devices are evaluated. However, medical devices are in many ways different from other products that are evaluated by the FDA. Most devices undergo constant evolution and have relatively short product life spans, and the engineering problems encountered during clinical use generally are sequentially addressed and resolved. In many instances, these devices are medical tools with clinical results that are heavily dependent on the skill of the physicians using them. In comparison, drugs go largely unchanged throughout much longer product life spans, and their therapeutic effects typically are less dependent on the physicians prescribing them.
Given the differences between drugs and devices, a uniform approach to device evaluation based on the FDA’s experience with nondevice products is likely to result in inappropriate clinical trial designs with the potential to slow or defeat marketing approval applications. For example, the double-blind placebo-controlled study that serves as the reference standard for drug evaluation is difficult or impossible to duplicate with devices, with which a procedure is generally necessary to use the product and the treating physician almost certainly knows whether the therapeutic intervention is being applied. In a similar respect, end points of medical device clinical trials to evaluate effectiveness must be adjusted to allow for operator experience and skill.
Treatment of genuinely new medical devices without predicates is problematic with the current regulatory system. These products are automatically considered to be class III devices, which technically must have premarket approval before they can be legally marketed. Down classification provisions do exist under FDAMA, but it remains to be seen how aggressively they will be applied in practice. For products that legitimately belong in other classes, there is the potential for considerable delay of their clinical application while data to support their reclassification are being gathered and administrative consideration is being given to the down classification process.
New devices that legitimately belong in class III, which are subject to the premarket approval process, also face potential considerable delays in clinical use for the reasons previously described. In either case, the clinical application of important new technology may be delayed. The elaborate process by which genuinely new products are evaluated by itself may discourage the development of truly innovative products, particularly that by smaller firms with limited resources, because the industrial community balances what is technically possible with what is more likely to gain timely marketing approval.
A Framework for Solutions to Regulatory Problems
The current regulation of medical devices reflects a societal decision to ensure the safety and effectiveness of medical products for their marketed indication(s), a principle that is very unlikely to be altered. Like any regulatory system, the current medical device regulation system has the potential to negatively affect the market it controls. However, FDAMA, with specific provisions and the general climate of cooperation and communication that it engenders, presents an opportunity for radiologists and the organized radiology community to continue their strong working relationship with the FDA to maximize the efficiency of the existing regulatory framework. In particular, the long-standing productive cooperation between the FDA and organizations such as the American College of Radiology, the Radiological Society of North America, and the Society for Cardiovascular and Interventional Radiology may serve as a foundation for affecting positive change through FDAMA.
The current indication-specific approval process can be improved to expedite the approval of important, state-of-the-art products as well as to minimize agency resources directed at evaluating relatively less important, lower risk products. The FDA has already acted to down classify a number of devices from class III to class II and thus lessen the regulatory burden on these devices (38). The radiology community must support these efforts and could take the initiative in suggesting additional specific products to be down classified. In addition, the support of our community in FDA efforts to establish outside review of 510(k) applications can contribute to the success of this program by helping to free FDA resources so that it can concentrate on high-risk products.
The availability of state-of-the-art technologies may be further enhanced by the aggressive use of FDAMA provisions to expedite the introduction of important new technologies. It is important that radiologists function as advocates for their patients when they believe that a new product represents a genuine breakthrough or when no viable alternative is available. Without such aggressive participation, the effect of these provisions is likely to be considerably lessened.
FDAMA, in conjunction with recent litigation, has created an opportunity for practical regulation of manufacturer distribution of information on off-label use. Such a solution carries with it the promise of moving state-of-the-art off-label uses into mainstream radiology practice more quickly. The radiology specialty societies, in conjunction with the industrial community and the FDA, can play an important part in successfully implementing the regulation of information on off-label use.
FDAMA directs the FDA to consider the least burdensome method of approving a new device, language that reflects the legislation’s overall goal of improving regulatory efficiency. The radiology community can play a major role in defining this largely undefined term by incorporating FDAMA’s mandate to recognize consensus standards. If properly defined and applied, the concept of least burdensome, with integrated device evaluation consensus standards, can speed up the introduction of new medical devices by describing how specific devices are to be evaluated. This ensures the appropriateness of the science applied to product evaluation while increasing the predictability of the process.
Finally, FDAMA down classification provisions may substantially address the problem of genuinely new devices without predicate products. Members of the radiology community can play a key role in assisting the FDA as the agency implements this concept, both with an overall framework and in the evaluation of specific products. In addition, because the least burdensome requirement is applicable to either 510(k) or premarket approval applications, it may be used in conjunction with the down classification provision to develop a comprehensive approach to the problem of genuinely new devices.
CONCLUSION
Modern medical device regulation under the FDCA is a complex endeavor with an inherent risk of impeding the development of new technology. FDAMA was enacted to combat this risk and establish mechanisms by which the overall regulatory goals of safety and effectiveness are maintained while the process itself is made more efficient. The legislation has also fostered an attitude of cooperation and communication between the FDA and the stakeholders in the device development process. However, the regulatory tools established by FDAMA cannot function by themselves or even with the enthusiastic support of the FDA: They are dependent on radiologists and the radiology community working with the agency to make a more efficient and workable regulatory system a reality.
http://radiology.rsna.org/content/218/2/329.full?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=quality+control+assurance&searchid=1125239307083_3402&stored_search=&FIRSTINDEX=40&sortspec=relevance
stole this from another poster i know of: pertaining to another company...but seems to fit here too, don't cha think.
"Big companies are looking for partnership, or buyout, with smaller companies with strong IP line [soon to be] already FDA approved product{s}. Specially now, when FDA is rolling out plan to change 510K approval procedure. New rules will be more stringent, more complex, and yes, more time consuming... It make more sense for "big guys" to act now, and scoop as many as they can FDA approved little guys.. When will we see FDA approval [clearance]? Only god, and FDA know."
made sense to me...
yes... keeping it simple, the process is a 510k (class 2) or PMA (class 3) when re: medical devices...
Premarket Notification 510(k) - 21 CFR Part 807 Subpart E
If your device requires the submission of a Premarket Notification 510(k), you cannot commercially distribute the device until you receive a letter of substantial equivalence from FDA authorizing you to do so. A 510(k) must demonstrate that the device is substantially equivalent to one legally in commercial distribution in the United States: (1) before May 28, 1976; or (2) to a device that has been determined by FDA to be substantially equivalent.
Premarket Approval (PMA) - 21 CFR Part 814
Product requiring PMAs are Class III devices are high risk devices that pose a significant risk of illness or injury, or devices found not substantially equivalent to Class I and II predicate through the 510(k) process. The PMA process is more involved and includes the submission of clinical data to support claims made for the device.
http://www.fda.gov/MedicalDevices/DeviceRegulationandGuidance/Overview/default.htm
joe, that post pertains to a PMA (pre-market approval), which is only applicable to a class 3 device, we are a class 2... class 2's have predicates and such applications are based on being substantially equivalent to their listed predicates. class 3 devices do not have predicates and thus need to apply with clinical data (trials) to support said application... but, both processes then are obviously evaluated by the FDA...
In the early to mid 1990s, fluoro came under the microscope due to induced-burns during certain types of procedures... the net-effect of that attention turned out very good for the use of the fluoroscope in general... raised awareness, etc.
as a matter of fact, the most notable recent aspect of the fluoro matter came from The Joint Commission, the accrediting commission of health care organizations...
on two fronts in one creed, they want this:
1.// specified actions taken when radiotherapy is applied to the wrong site...
2.// specified actions taken when fluoroscopic radiation dose is greater than anticipated for the given procedure... moreover, note, the american academy of physicists in medicine, as a group concensus strongly/proactively advocated that the wording/phrasing of this component of the two-part creed included, this part "...greater than anticipated for the given procedure."
NOTE: i am paraphrasing the wording for both (1) and (2), but you get my point.
now, for hopsitals, etc., to become accredited with flying colors... something that hospitals administrators truly strive to acquire ~ that is, accreditation by The Joint Commission, they must show in-place actions plans/contingencies for such incidences.
so, to carry out my point, i think we may likely see something similar to this for CT scanning.
*****
i want to stress this though, both fluoro systems and current CT systems can show the cumulative dose received during its use for the procedure/exam. it's an interpolation based on multiple factors, and is found under the heading, and thus referred to as, the "dose summary."
GE and lawsuit...
Lawsuit hits GE in Alabama CT overdose case
By Eric Barnes
AuntMinnie.com staff writer
December 18, 2009
Attorneys in Huntsville, AL, have filed suit in federal court against GE Healthcare of Chalfont St. Giles, U.K., on behalf of a patient who allegedly received excessive radiation during a CT perfusion head scan for suspected stroke.
The patient, Becky Coudert, will be the lead plaintiff in an Alabama-based class-action lawsuit representing more than 300 patients, including many of the 260 patients who allegedly received CT overdoses at Cedars-Sinai Medical Center in Los Angeles. A previous class-action suit filed in California has been withdrawn, attorneys representing the plaintiff said.
The class-action complaint was filed on December 15 in the U.S. District Court for the Northern District of Alabama on behalf of Coudert, who received a CT perfusion scan in August 2009 at Huntsville Hospital for suspected stroke. The lawsuit was filed by Huntsville, AL-based Watson, McKinney & Artrip.
The attorneys allege that Coudert received a dose of 5.9 Gy during her perfusion study, leaving her with persistent and debilitating symptoms including memory loss, depression, and dizziness. The dose was about 1,000 times the normal exposure, according to Rick Patterson of law firm Owen, Patterson & Owen in Los Angeles, which is working in cooperation with the Alabama attorneys on the case.
The patient's one visible mark from the overexposure was hair loss in a ring that extended around the head and over the temples. Coudert initially contacted the Huntsville firm after she recognized her own symptoms in news reports of radiation overdoses at Cedars-Sinai, Patterson said.
Plaintiffs are asking for $5 million for the purposes of monitoring any future cancers that might arise in the approximately 300 patients, in addition to changes in scanner design and imaging personnel practices, and damages that will vary for each case, Patterson said.
The lawsuit claims that GE's scanners should have been designed to provide more warning when excess radiation beyond a normal protocol is about to be applied, according to Patterson.
"The machine doesn't have a beeper on it" to warn of a pending high-dose exam, Patterson said, nor does it have any kind of prompting system to ensure that the physician or technologist knows that a high-dose exam is about to be delivered.
In a statement, GE said that no scanner malfunction has been identified in any of the Alabama or Cedars-Sinai cases, and patient dose was determined solely by the medical team onsite at the hospitals. The company is aware of litigation regarding the Alabama incident but is unable to comment on the specifics as a matter of policy.
"Although GE Healthcare continues its internal investigation, we confirm that there were no malfunctions or defects in any of the GE Healthcare equipment involved," the statement said. "GE has also confirmed that the GE scanners at Huntsville Hospital are operating as intended. As with all CT head perfusion scans, the radiation dose delivered was a decision made by healthcare providers during the treatment of stroke patients. This decision was based on the medical expertise of the Huntsville staff as well as the needs of the patients."
GE said it is also cooperating with U.S. Food and Drug Administration (FDA) officials, and is working closely with Huntsville Hospital to review and optimize its CT protocols per the FDA's October and December recommendations. In October, the FDA said it had learned of the CT overdose cases at Cedars-Sinai; earlier this month, it said that other cases had come to light in the U.S., including some at an Alabama hospital.
GE "continues to offer dose-reducing technologies and expand key CT training initiatives to raise awareness of dose optimization and use of appropriate exam protocols," the statement continued. The company's CT products require that users carefully evaluate user-defined scanning protocols, and the recommended dose is an "important clinical decision" that should be made by qualified medical personnel.
In addition to Coudert, Patterson said that approximately 60 people scanned at Huntsville Hospital have come forward saying they may have been overdosed during perfusion CT scans -- largely perfusion CT studies of the head undertaken to rule out stroke.
Patterson said the scanners are serviced and calibrated in a routine annual or biannual process that involves the manufacturer -- and that the Huntsville scanner had recently been adjusted before the patient was treated.
"Like so many effective medical tools, devices, and pharmaceuticals, the more beneficial they are, they also have a contrasting danger side," Patterson said. "We hope that one of the results of the review of these cases ... will be a focus on safety systems, both in consistency of prescribed doses and the frequency of doses" to the patient, "resulting in improved practices," he said.
By Eric Barnes
AuntMinnie.com staff writer
December 18, 2009
mr. sano, i'll get back to ya...eom.
mr. sano, i'll get back to ya...
i'll bite, send/forward to me goldcoastoh@yahoo.com
kingfisher: re: your questions...
for radiologists: board certification prior to 2002 is lifetime, it is 10-YEAR time limited after that...
note: residents going into residency in 2010 will begin an integrated certification exam schedule - this will be multiple steps with picture intense portions (not just written portions) along with everything else, i.e., physics etc.
for radiologic technologists: time limited certification examinations will begin soon...
note: just because the time limited thing certification is becoming mainstream, doesn't mean they are dropping the need to maintain your license/certification with continuing education credits...
re: human error: it appears as though over-radiation with CTs has been built on "preferences" associated with setting up the parameters for the imaging algorithms, or "errors throughout the community in not having had them standardized," or with some sites not following recommendations by the american college of radiology, which amongst other things serves as an accredentialing body for sites... a "must have" when speaking about sites with MRI machines.
the DViS does realtime 3D fluoroscopy... (the thing new here is the 3D part (as fluoroscopy is by "definition," realtime, really means to view with light)... the DViS is a surgical/interventional physician scope or tool... a fluoroscope.
the cone beam CT feature is the icing on the cake... so, have your cake and eat it too.
yes, i'm in the field...
my reply to sexyladyfitness: re: images.
http://messages.finance.yahoo.com/Stocks_%28A_to_Z%29/Stocks_I/threadview?m=tm&bn=34920&tid=29993&mid=30789&tof=1&frt=1
i chose not to attend RSNA although it would not have been that far of a drive to go...and a really close flight. i had another conference to attend...
i enjoyed the dialogue on the 12/9/09, conference call between the cardiologist and dean, they came to a middle ground...and the cardiologist provided some good insights for how he sees the role of the DViS in his discipline.
images, in a minute... let me say, this first, you know why dean hasn't shown the images yet... he doesn't want to A.) 'disrupt' the FDA, and B.) (although patent-protected) let other corporations glean any insights...
ALSO, i'm really surprised people here are not complaining or whatever about dean not having the fully functional DViS at RSNA... again, see the paragraph directly above (part B). although, even if he did, no one is allowed to operate their equipment at the conference/tradeshow.
*****
now, pertaining to images, i absolutely have to show you pictures from what i consider to be the most relevant article, it is my opinion that the DViS real-time 3D will appear as these images appear from the, "Use of a C-Arm System to Generate True Three-dimensional Computed Rotational Angiograms."
NOTE: ALL THESE 3D IMAGES ARE RECONSTRUCTED IMAGES... they are obtained by modifying a biplanar fluoroscopy system...
NOTE: The DViS will remedy many of the issues of this technique as described in the article. But, all i have time for tonight is to post this message: look at page 1511. but, i will go over why i say this later...
http://www.ajnr.org/cgi/reprint/18/8/1507.pdf
Figure 2:
Fig 2. Comparison of a single 3-D volume reconstruction of an anesthetized pig with the original 2-D radiographic projections.
A and C, Lateral and anteroposterior views in MIP through the 3-D volume.
B and D, 2-D lateral and AP projection images, matched to A and C. Note the faithful reconstruction of small vessels in the MIP images as compared with the vessels that are visible in the 2-D projection images.
E, Craniocaudal MIP image through the 3-D volume. This view is not normally available to the interventionalist during patient treatment. The small, straight object (center bottom) to the right of the carotid indicates the presence of a high-contrast marker within the endotracheal tube.
CT fluoroscopy improves lung biopsy accuracy
By Reuters Health
December 16, 2009
NEW YORK (Reuters Health), Dec 16 - Lung biopsies guided by CT fluoroscopy have a higher diagnostic yield than biopsies guides by conventional CT, Japanese researchers report in the December issue of Chest.
The results show "high diagnostic accuracy even for small lesions; this is presumably thanks to the use of CT fluoroscopy," lead author Dr. Takao Hiraki told Reuters Health.
Dr. Hiraki and colleagues at Okayama University Medical School retrospectively evaluated 1,000 lung biopsies performed with 20-gauge coaxial cutting needles in 901 patients.
The results were non-diagnostic in 0.6%. The authors point out that this rate compares favorably with the 3.3% non-diagnosis rate seen in a study of 846 biopsies performed with conventional CT guidance and 20-gauge or 21-gauge aspiration needles or core needles.
In the current study, the sensitivity of CT fluoroscopy-guided biopsy for diagnosis of malignancy was 94.2% and the specificity was 99.1%. The overall diagnostic accuracy was 95.2%, and for lesions of 1.0 cm or less it was 92.7%.
Factors independently associated with diagnostic failure were having two or less specimens (odds ratio, 2.43); lesions in the lower lobe (OR, 2.50); malignant lesions (OR, 7.16); and lesions smaller than 1.0 cm (OR, 3.85) or larger than 3.1 cm (OR, 4.32).
The team also notes that "the use of the coaxial needle system contributes to a high diagnostic yield because this system may facilitate the acquisition of multiple specimens."
"In this study," they add, "three or more specimens were collected for 52% of the lesions."
By David Douglas
Chest 2009;136:1612-1617.
Last Updated: 2009-12-15 20:39:10 -0400 (Reuters Health)
*****
a youtube video showing percutaneous pulmonary biopsy with real-time CT fluoroscopy: although likely not from these researchers:
fail safe: mr. sano
first, for fluoro c-arms, there is sorta a dead man switch like in mobile x-ray but not really... but, obviously, if you take your finger foot of the switch pedal you no longer emit.
also, there is an audible tone and visual light when emitting, and each of these are different between normal dose and high dose (boost) settings.
there also exists a manual over-ride "shut off" switch to turn the entire apparatus off.
there are exposure rates which appear on the monitor in mobile c-arm fluoroscopy...
there is an alarm which you must turn off in order to quiet it, at every 5 minute mark. this, doesn't mean you can no long image the patient... its just serves to let people know 5 minutes elapsed.
some, if not all of these things are required by regulations.
again, the annual/biannual physics acceptance tests help optimal operation of the device so that patients are not being over-radiated...
as well as, annual preventative maintenance by field engineers...
c-arms default to "automatic brightness control" meaning the maching knows how much exposure is necessary and adjusts your "power" accordingly... this id done by knowing how much is being emitted and how much is being received (or thusly, how much is being attenuated)... of course the operate can over-ride this in order to reduce dose if necessary... or adjust as necessary...
you can also collimate the beam... via lead shutters in order to form the beam and radiated as little area as possible, for instance, a super c-arm has an field of view of 23 cm in normal magnification mode (i.e., no magnification)... the geometries are set that the opening from the housing unit/x-ray tube are such that it (the opening) is only big enough to meet that max radius (23 cm)... however, you can use octagonal lead shutters which are radio-opaque and thus heavily lead lined in order to reduce the area, buy remember if you halve the perimeter you decrease area irradiated by a power of four... this use of the shutters is called collimation and the proper term is collimate... afterall, you only want to see your region of interest... there also exist semi-transparent lung leaves shutters... which you can also use at the same time. with some large body types (habitus) you may need to leave the shutters open though just so you get as much photons to the image receptor as possible, since the larger one is the hard it is to get photons through them without being attenuated.
you gotta remember, when talking fluoro, we are all in there in the moment... it is a "surgical/interventional tool." it is a scope.
***
the testing, both physics-wise and field engineer-wise are also performed on CT scanners.
regarding CT scanners, they are calibrated way more frequently with 'phantoms' i.e., dummies...
there some or some CT going forward which will adjust exposure factors, i.e., your penetrating "power," imaging technique to meet the subject/patient requirement durig what is called a scout scan... this is mentioned in the article i posted on CT scanners from M MAHESH... this will serve as sort of an "automatic brightness control" feature in the realm of CT scanners...
***
everything is multi-faceted...
pablo -- according to the paper i posted tonight on portable CT scanner for head scanning...
"The economic advantages of this technology make it a viable
option for improving patient care. A cost analysis done on
the use of the CereTom (NeuroLogica, Danvers, Mass) at a
level I trauma center calculated a return on investment of
169%.1 These calculations took into consideration the cost of
the machine, $359,000, and the single technician needed to
operate it. The costs were weighed against those of personnel
and equipment needed for the transport of a patient to and
from the conventional scanner."
http://www.ajnr.org/cgi/reprint/30/9/1630?maxtoshow=&HITS=60&hits=60&RESULTFORMAT=&fulltext=three+dimensional+fluoroscopy&andorexactfulltext=and&searchid=1&FIRSTINDEX=0&sortspec=relevance&resourcetype=HWCIT
LET ME ADD THE DViS, IMHO, WILL OFFER FAR MORE COST-ADVANTAGE... BECAUSE IT IS A FLUOROSCOPY SYSTEM... IT'LL ENABLE FLUOROSCOPICALLY GUIDED IMAGERY AS ITS FOREMOST FEATURE...
ALTHOUGH PRICED MORE THAN THE CERETOM, MOST CONE-BEAM CTs ARE IN THIS BALLPARK AS WELL, BUT I BELIEVE THE DViS IS PRICED LESS THAN THE MEDTRONIC O-arm... WHICH I BELIEVE BECAUSE THE MEDTRONIC 0-arm IS NOT A TRUE GANTRY (IN THE PUREST SENSE) IT WON'T EVER BE ABLE TO DO WHAT THE DViS DOES.
Portable CT brings lower costs, reduced risk to ICU
By Eric Barnes
AuntMinnie.com staff writer
September 10, 2008
Hospitals can save time and money by bringing CT scanners to intensive care patients rather than the other way around, according to a study from the Cleveland Clinic in Ohio. Study authors Dr. Thomas Masaryk and colleagues hailed the reduced personnel utilization and lower risk of scanning the patients bedside with a portable CT scanner.
"CT imaging has become an increasingly valuable diagnostic modality for Intensive Care Unit (ICU) patients, and radiographic findings often significantly impact clinical management," they noted. "However, many clinicians may be reluctant to perform CT imaging on hemodynamically unstable ICU patients, as there are both risks and logistical difficulties associated with the transport of such patients" (Radiology Management, March-April 2008, Vol. 30:2, pp. 2-6).
Staff routinely accompanies ICU patients to the radiology department to complete scans, boosting the cost of care and taking up valuable staff time. Even with such assistance, the risks of transporting the patients are substantial. The authors cited a study by Weissman and colleagues that demonstrated a 13% increase in morbidity associated with transporting ICU patients to the operating room.
In another study, Smith and colleagues from Cooper Hospital and University Medical Center in Camden, NJ, found that adverse events such as disconnection of ventilators and monitoring equipment occurred on a third of all transports outside the ICU in a group of 125 patients. "Transport specifically to the CT suite was associated with a 71% incidence of adverse events," Masaryk and his team wrote of patients transferred within the hospital (Critical Care Medicine, March 1990, Vol. 18:3, pp. 278-281).
"To address concerns for patient safety, resident physicians, nurses, and respiratory therapists accompany ICU patients during transport," Masaryk and his team wrote. "As many as five staff members may be required for transport, and the nurse-to-patient ratio in the ICU may increase from 2:1 to 2.5:1 as a consequence."
An initial assessment of the number and types of scans performed on ICU patients showed that 1,700 scans per year, or approximately half of all CT scans, were performed on patients in the neuropathology/neurosurgery ICU. For this reason, the researchers decided to dedicate the use of their eight-slice mobile CT scanner (CereTom, NeuroLogica, Danvers, MA) to neurology and neurosurgery patients in the ICU.
The scanner is equipped to perform noncontrast CT, CT angiography (CTA), CT perfusion, and Xenon perfusion studies, the team noted. Scans are performed by cantilevering the patient's head off the end of the bed onto a carbon graphite scan board.
Prior to acquisition of the scanner, the researchers counted a total of 6,145 head CT studies, including 5,369 (86%) noncontrast head scans, 440 (7%) CTA studies, 300 (5%) neck studies, and 137 (2%) perfusion studies.
They also calculated the costs of patient transport based on estimates of salaries and benefits ranging from $72,000 for ICU nurses and resident physicians to $60,000 for respiratory therapists and radiologic technologists, as well as $24,000 for transportation assistants.
Based on these estimates, the group estimated personnel costs of $97 for each transport to the radiology department, in addition to $19 per study for the cost of technologists during a conventional scan.
For the study, the portable scanner was tasked with only the noncontrast head studies, representing the largest portion (86%) of neuroradiology scans performed before its acquisition.
During the four-month study period, 502 studies were performed on the portable scanner in a mean time of 18 minutes, versus 50 minutes for a conventional scan plus transports.
Total technologist costs with the portable device were $9 per scan for a single technologist, versus $19 for two technologists with the conventional scanner. The mean $97 cost of transport was eliminated entirely when the portable scanner was used.
For the 502 scans performed on the portable scanner, estimated personnel costs for conventional scanning were reduced from $58,689 to $4,518 with use of the portable scanner, yielding projected annual cost savings of $162,512.
Use of the portable scanner also enabled a greater number of outpatient scans to be obtained: an additional 394 scans over the four-month study period yielded additional revenues of $153,715, for an estimated annual increase in revenue of $461,145, Masaryk and colleagues wrote.
There are a number of risks associated with patient transport, leading to delayed or deferred CT imaging in some cases, the authors explained. "The availability of a portable scanner would allow for neuroimaging in even the most unstable patients, for whom transport to the radiology suite is contraindicated," they wrote. "Bedside imaging may provide clinically relevant data in patients for whom CT imaging may otherwise have been unobtainable."
As for limitations, the portable scans were obtained in about 25% of all inpatient head CT studies. Also, due to space limitations, the scanner had to be stored on a separate floor of the hospital from ICU patients, requiring two technologists to move it to the floor to conduct imaging studies. The cost of transporting the scanner from the floor where it was stored was not included in the cost results. Finally, the scanner requires manual timing for contrast scans, potentially reducing the quality of cerebrovascular imaging studies. The manufacturer has since developed an automated bolus tracking software, they noted.
When all the cost savings are added up, "introduction of the portable scanner may offer a net economic benefit of $264,000 in the first year of its operation and a total benefit over five years greater than $2,619,000," Masaryk and his colleagues concluded.
By Eric Barnes
AuntMinnie.com staff writer
September 10, 2008
cone-beam CT and radiotherapy...
dean has stated he sees no reason why the DViS can't be applied for - for this use after - initial clearance is received...
here's an interesting pdf from the AAPM, the american academy of physicists in medicine, it's a large file but worth... plenty of images, etc...
http://www.aapm.org/meetings/06SS/documents/SonkeConeBeam.pdf
hey pablo - thought you said OR, not ER, but i mean yes there are but very site dependent to my knowledge... i feel most confortable citing the literature as an example... i mean in the ER a priority use is that one wants to make sure we aren't looking at hemorrhagic (but rather ischemic) stroke prior applying the 'clot buster', whether it's assessed via portable or fixed CT.
i'm not sure if the below study used a cone-beam portable CT or not, my guess is not... some feel that cone-beam CTs aren't feasible quite yet for brain imaging... i feel that is only a temporary technologic issue though.
Radiol Manage. 2009 Mar-Apr;31(2):41-5.
Portable CT imaging of acute stroke patients in the emergency department.
Weinreb DB, Stahl JE.
Department of Radiology, Hospital of Saint Raphael, New Haven, CT, USA.
A study was performed to determine whether the use of a portable CT scanner dedicated for ED patients would reduce the time elapsed from the physician's request for CT imaging until the start time of the study. The portable scanner allowsfor more rapid assessment of stroke patients and does not require additional facilities or personnel. In addition, when not in use in the ED, the scanner couldbe transported elsewhere in the hospital, for example the ICU, and be available for alternative clinical applications. For most hospitals, it is not neccessary to invest in an additional CT scanner dedicated for stroke imaging in the ED unless demand for the scanner exceeds 60 patients per day or, alternatively, the prevalence of stroke in the community served by the hospital is approximately 4-5 times the national average.
PMID: 19634797 [PubMed - indexed for MEDLINE]
yes there are pablo... for a quick primer, using intra-operative head-ears-nose-throat procedures as an example, look here:
quick excerpt:
Portable CT Scanners
In discussing portable CT equipment, we will make a distinction between the MSCT and CBCT machines.
AJNR Am J Neuroradiol Rumboldt et al. 30 (9): 1630-1636.
http://www.ajnr.org/cgi/reprint/30/9/1630?maxtoshow=&HITS=60&hits=60&RESULTFORMAT=&fulltext=three+dimensional+fluoroscopy&andorexactfulltext=and&searchid=1&FIRSTINDEX=0&sortspec=relevance&resourcetype=HWCIT
Review of Portable CT with Assessment of a Dedicated Head CT Scanner
Z. Rumboldt, W. Huda, J.W. All
SUMMARY: This article reviews a number of portable CT scanners for clinical imaging. These include the CereTom, Tomoscan, xCAT ENT, and OTOscan.
The Tomoscan scanner consists of a gantry with multisection detectors and a detachable table. It can perform a full-body scanning, or the gantry can be used without the table to scan the head.
The xCAT ENT is a conebeam CT scanner that is intended for intraoperative scanning of cranial bones and sinuses.
The OTOscan is a multisection CT scanner intended for imaging in ear, nose, and throat settings and can be used to assess bone and soft tissue of the head.
We also specifically evaluated the technical and clinical performance of the CereTom, a scanner designed specifically for neuroradiologic head imaging. The contrast performance of this scanner permitted the detection of 4-mm low-contrast lesions, and the limiting spatial resolution was 7 line pairs per centimeter. The measured volume of the CT dose index (CTDIvol) for a standard head CT scan was 41 mGy (120 kV/14 mAs). All clinical images were of diagnostic quality, and the average patient effective dose was 1.7 mSv. We conclude that the CereTom portable CT scanner generates satisfactory clinical images at acceptable patient doses.
now mr. sano, with respect emitter device control...
i don't know specifically but infer it is as it is with any c-arm...
dean stated a foot pedal...
c-arms have this...
moreover, let's consider the OEC c-arms...
they emit via the following ways:
1.// foot pedal... tap it and take one instant picture, step and hold and image live. as well, this has a boost radiation level option. boost is used for big body types... you simply need to increase your "power" to penetrate a large body habitus (type).
2.// button... tap it with finger and and take one instant picture... hold button down longer and take live images...
3.// coiled tethered hand remote... quick push of this button, again for a simple frame/image... or hold the button for live fluoro... this remote also has an option for boost fluoro...
now, on the control panel you may select the "low dose" feature... this reconfigures your "power" to become dose sparring... when this feature is selected, then both the aforementioned regular and the boost pedal/buttons operate at this stepped-down feature...
finally, you may also select "pulsed" fluoro on the control panel... when you image live with pulsed the images on the monitor look as if you're under a strobe light... as a matter of fact the patient is... because the emitter is emitting in pulses...
when you combine low-dose and pulsed, you have significant dose savings...
as a matter of fact in pulsed mode all time is different, for instance, 10 seconds in pulsed fluoro mode, can equate to 30 or more or so seconds in continuous (non-pulsed) mode...
now, this is fluoro time only... not total procedure time... you for example, on any given day we may use between 4 seconds to 1 minute 38 seconds of fluoro time... these procedures can take between 15 minutes and 40 minutes... for patient to patient turnover... in an ambulatory sorta sort of setting.
one of our studies shows we have fluoro time ranging from 19.5 seconds to 304 seconds... all under "low-dose" and using pulsed mode as frequently as possible. and all pertaining to the same type of procedure... again, the procedure may be as quick as 20 minutes to as long as 50 minutes.
important to note these times for fluoro are not straight across the timeline times... they may be instant image every so often. i.e., intermittently applied... this is also good imaging practice...
mr. sano re: calibration/mechanical
FDA finds new cases of CT radiation overexposure
By Brian Casey
AuntMinnie.com staff writer
December 7, 2009
The U.S. Food and Drug Administration (FDA) said that it has found additional cases of radiation overexposure related to CT brain perfusion scans. The new cases occurred at hospitals besides Cedars-Sinai Medical Center in Los Angeles and involve more than one CT manufacturer.
In a December 7 news conference, the FDA updated the media on the status of its investigation and gave healthcare providers guidance on steps to take to reduce unnecessary radiation during CT scans. The news conference was a follow-up to a news story that broke in October, when the agency said it was looking into a case in which 206 patients received up to eight times the recommended radiation dose at Cedars-Sinai.
The patients were scanned on equipment manufactured by GE Healthcare of Chalfont St. Giles, U.K., but the scanning protocol apparently was developed by Cedars-Sinai healthcare staff.
Since then, the FDA has discovered additional patients at Cedars-Sinai who received excessive exposure, bringing the total to 250. What's more, the agency has received a report of 14 patients who were overexposed at Glendale Adventist Medical Center in Glendale, CA, as well as a similar report from Providence St. Joseph Medical Center in Burbank, CA. Finally, the FDA has received reports of overexposures in other states, such as Alabama.
Some of the new reports involved GE scanners, but the agency said that at least one overexposure case involves a scanner manufactured by Toshiba America Medical Systems of Tustin, CA. The agency did not say which facility used the Toshiba system.
The FDA declined to comment on whether its investigation indicated that the overexposure cases were caused by human error in operating the scanners, or if there were basic flaws in the CT systems that caused the incidents. Until then, the agency is recommending that CT sites take extra vigilance in setting their scanning protocols, and it provided several recommendations:
* Imaging facilities that perform CT perfusion scans should assess whether patients who have received CT perfusion scans have received excess radiation.
* Facilities should review their radiation-dosing protocols for all CT perfusion studies to ensure that the correct dosing is planned for each study.
* Facilities should implement quality control procedures so that dosing protocols are followed every time and the planned amount of radiation is administered.
* Radiologic technologists should check CT scanner display panels before performing a study to make sure that the correct radiation dose will be used.
* If more than one study is performed during one imaging session, practitioners should adjust the dose of radiation so that it is appropriate for each study.
While the recommendations might seem self-evident, healthcare facilities can sometimes lose track of radiation dose over time when using specially developed scanning protocols, said Dr. Jeffrey Shuren, acting director of the FDA's Center for Devices and Radiological Health.
"What happens over time is that facilities may wind up using particular algorithms that will then calculate the radiation exposure for a particular test," Shuren said. "Sometimes those algorithms are designed to encapsulate multiple tests. What we are suggesting here is that until such algorithms are validated, make sure it is the proper dose for that particular patient before initiating the study."
A representative from GE Healthcare said that its internal investigation has found no malfunctions or defects in any of the scanners involved. The Alabama case, at Huntsville Hospital in Huntsville, was the result of "a medical decision made by the staff there," and the GE scanners at the facility are "operating as intended."
"As with all CT head perfusion scans, the radiation dose delivered was a decision made by healthcare providers during the treatment of stroke patients," a GE statement said. "Patient safety continues to be the primary concern of Huntsville Hospital, and GE Healthcare will continue to support in providing user training on dose-reducing technologies and methods."
Meanwhile, a Toshiba spokesperson said the company is cooperating with the FDA investigation.
"The FDA has informed us of one site where potential overradiation has occurred on a Toshiba system," the spokesperson said. "We are cooperating fully with the FDA and working with them to investigate this matter."
By Brian Casey
AuntMinnie.com staff writer
December 7, 2009
hi mr. sano... this post is quite long -- it's a copy and past from an auntminnie reporter... i am taking the liberty to cut and paste this giving him credit of course because i want to highlight a few things in it...
Studies spotlight high CT radiation dose, increased cancer risk
By Eric Barnes
AuntMinnie.com staff writer
December 14, 2009
Two studies appearing in this week's Archives of Internal Medicine reveal higher-than-expected radiation dose in clinical CT studies and increased lifetime potential cancer risks as a result. At a minimum, the U.S.-funded studies suggest that dose-reduction efforts have not spread widely enough across the U.S.
The ambitious multicenter studies aren't the first to sound the radiation alarm, of course. Trailing just slightly behind the decade's explosive growth in CT imaging studies has been the increase in peer-reviewed articles warning of the dire health consequences of CT scanning.
In 2009 alone, studies published or reprinted in JAMA, a sister publication to Archives of Internal Medicine, have warned that repeat calcium scans are a cancer threat, and coronary CT angiography doses remain high and widely variable. An August study in the New England Journal of Medicine warned that radiation exposure to the population is growing -- and largely attributable to the growth of CT imaging.
In response, radiology's defenders have emphasized the challenge of making cancer projections based on atomic bomb survivor data, and the lack of evidence that growth in the number of scans is leading to more cancers. Imaging advocates have also emphasized the value of clinical decisions made possible by CT scans, and the risks of not performing clinically indicated studies.
Two fronts
Today's studies and accompanying editorial approach the CT dose and risk question on two fronts. One, a multicenter study sponsored by the U.S. National Institutes of Health (NIH) and the National Cancer Institute (NCI) in Bethesda, MD, estimates the number of cancers that would arise from all CT studies performed in the U.S. during a single year, 2007.
Some 29,000 future cancers could be related to CT scans performed in 2007 alone, according to Amy Berrington de Gonzales, Ph.D., and colleagues from the NCI, who based their estimates on the 2006 Biological Effects of Ionizing Radiation (BEIR) VII risk models.
The biggest contributors to dose? Abdominal and pelvic scans, followed by chest studies. (Reprinted in JAMA from the Archives of Internal Medicine, December 14-18, 2009, Vol. 169:22, pp. 2009-2071.)
A second study, by Dr. Rebecca Smith-Bindman from the University of California, San Francisco (UCSF) and colleagues from several Bay Area institutions, used clinical data from national databases to evaluate the radiation doses from several common CT imaging exams (reprinted from Archives of Internal Medicine, December 14-18, 2009, Vol. 169:22, pp. 2072-2078).
The authors of this study, also supported by the NIH and NCI grants, said they were surprised to find that radiation doses for common CT exams were higher and far more variable than previous estimates. Within each type of CT study, effective dose varied significantly both within and across institutions, with a mean 13-fold variation between the highest and lowest dose for each study type.
CT's popularity is high for many reasons, ranging from its speed and increasing ease of use, to the relentless development of new imaging techniques, to a growing body of evidence showing its images throughout the body to be reliable for diagnosis. Unfortunately, drivers of increasing scan volumes also include the lure of monetary rewards, particularly for in-office procedures, and the practice of defensive medicine -- unnecessary scans performed to minimize the threat of a lawsuit resulting from a missed diagnosis.
As these two studies make clear, radiation doses are higher than previously thought. They also demonstrate that radiation dose reduction is not yet a universal phenomenon and raise further doubt about whether the risk/benefit ratios and alternatives to CT scanning are seriously considered for every patient and CT scan.
One year of CT scans: 2007
The use of CT scans has increased more than threefold since 1993, to approximately 70 million scans per year, noted Berrington de Gonzales in her group's study of estimated cancer risks from CT scans.
"The rapid increase in the U.S. has raised concerns about potential cancer risks, because when a large number of people are exposed, even small risks could translate into a large number of future cancers in the population," the authors wrote.
Their study includes detailed estimates of future cancer risks based on current CT use according to sex, age, and scan type. They estimated the frequency of different types of CT scans performed in the U.S. in 2007 using several data sources, including Medicare claims and a survey of CT scan use from IMV Medical Information Division of Des Plaines, IL, that covered 2,451 facilities. NCI data were used to address the question of expected survival.
Models based on the BEIR VII report were then combined with age- and sex-specific scan frequencies obtained from survey and insurance claims data.
The results for the projected number of incident cancers per 10,000 scans generally decreased with increasing age at exposure and varied according to scan type, they wrote. Risks were consistently high for chest or abdomen CT angiography and whole-body CT, and still higher in women due to the additional risk of breast cancer and higher lung cancer coefficients.
From a total estimate of 72 million CT scans performed during the year, the authors estimated 29,000 (95% UL, 15,000-45,000) future cancers would develop that could be related to CT scans.
The largest contributors to the risk were scans of the abdomen and pelvis (n = 14,000; 95% UL, 6,900-25,000), followed by chest (n = 4,100; 95% UL, 1,900-8,100), head (n = 4,000; 95% UL, 1,300-5,000), and chest CT angiography (n = 2,700).
Lung cancer was the most common radiation-related cancer (n = 6200; 95% UL, 2,300-13,000), followed by colon cancer (n = 3500; 95% UL, 1,000-6,800) and leukemia (n = 2800; 95% UL, 800-4800).
"The cancer sites with the highest risks were common cancers with a high frequency of exposure to that organ (e.g., colon from CT of the abdomen and pelvis and lung from CT of the chest) or higher radiosensitivity (e.g., red bone marrow and leukemia)," Berrington de Gonzalez et al wrote.
Although most of the focus on CT radiation doses has been on pediatric cases, the study data suggest that greater numbers of adult patients will be harmed from CT-induced radiation doses. The data are unique in that they are based on cancer risks in current U.S. age- and sex- specific scan patterns, they noted.
Age trends were also seen in the results. One-third of the estimated cancers came from patients in the age range of 35 to 54 years, compared to 15% of cancers in patients younger than 18 years. Fully 66% of the projected cancers were in women.
The risks according to the study results are much higher than the commonly quoted estimate of one death per 2,000 scans because of the younger age distribution of patients currently undergoing CT in the U.S., Berrington de Gonzales and colleagues wrote.
"Although cancer risk from CT scans have not been demonstrated directly, radiation is one of the most extensively studied carcinogens, and there is direct evidence from studies of the Japanese atomic bomb survivors, nuclear workers, and patients receiving multiple diagnostic x-rays that radiation doses of the magnitude delivered by several scans (5-10 rad) can cause cancer, and that the magnitude of the risk at these doses is largely consistent with the risks at higher doses," they stated.
Changes made to scanning practices now could help avoid the possibility of rising cancer incidence, they concluded. The estimates "highlight several areas of use in which the public health impact may be largest, specifically abdomen and pelvis and chest CT scans in adults aged 35 to 54 years."
Radiation doses high in common CT exams
In the second study, Smith-Bindman et al sought to estimate the radiation dose associated with common CT studies in clinical practice and quantify the potential cancer risk associated with these examinations.
"Although CT is associated with substantially higher radiation exposure than conventional radiography, typical doses are not known," they wrote.
The retrospective cross-sectional study described the radiation dose associated with the 11 most common types of diagnostic studies, including head; chest, cervical, thoracic, and lumbar spine; CT angiography of the chest and other regions; whole-body CT; virtual colonoscopy (also known as CT colonography or CTC); calcium scoring; and other CT exams.
The data covered 1,119 consecutive adult patients at four institutions in the San Francisco Bay Area who were scanned during the first half of 2008. Using their risk models, the investigators estimated lifetime attributable risks of cancer by study type from the measured doses.
The results showed that radiation doses varied significantly between different types of CT studies -- and within the same types of CT studies. Among different exam types, median effective doses ranged from 2 mSv for a routine head CT to 31 mSv for a multiphase abdomen and pelvis CT.
"Within each type of CT study, effective dose varied significantly within and across institutions, with a mean 13-fold variation between the highest and lowest dose for each scan type," they wrote. "The estimated number of CT scans that will lead to the development of a cancer varied widely depending on the specific type of CT examination and the patient's age and sex."
For example, an estimated one in 270 women who underwent CT coronary angiography at age 40 will develop cancer from that CT scan (one in 600 men), compared with an estimated one in 8,100 women who had a routine head CT scan at the same age (one in 11,080 men).
For head and neck scans, the median effective dose varied from 2 mSv for a routine head scan (IQR, 2-3 mSv) to 14 mSv (IQR, 9-20 mSv) when imaging for suspected stroke. In the chest, the median effective dose varied from 8 mSv (IQR, 5-11 mSv) for a routine chest to 22 mSv (IQR, 14-24 mSv) for coronary angiography. For abdominal and pelvic scans, a routine CT scan without contrast had the lowest median effective dose (15 mSv; IQR, 10-20 mSv), whereas a multiphase abdominal and pelvis CT scan had the highest median effective dose (31 mSv; IQR, 21-43 mSv).
The authors attributed the surprisingly high median effective doses to three causes. First, they said, estimated doses in the study were received by real patients in clinical practice, which may routinely deliver higher doses than those logged in idealized settings or using a phantom.
Second, most reported doses in the literature are from single-center studies where the protocols may be standardized, in contrast to doses in the present study gleaned from individual patients across multiple institutions, the group explained.
Finally, most prior studies grouped together exams from the same anatomic area, even though not all CT scans involve similar doses due to differences in patients (increasing scan length for some) and the clinical question being addressed by the imaging study.
Two factors loomed as dose drivers in the study. In every anatomic area, studies that included an assessment of arteries, as well as multiphase studies, had higher exposures due to the use of repeated scans for these study types.
How to lower dose
Recommendations for lowering the doses include:
* Standardizing protocols across sites
* Reducing multiple imaging series within each exam (multiphase studies)
* Implementing dose-reduction strategies
* Participating in accreditation programs such as those offered by the Reston, VA-based American College of Radiology (ACR)
Reducing the number of CT exams is also important because reports suggest that 30% or more of CT scans may be unnecessary, they stated. Cumulative patient dose information should be tracked and monitored.
"A searchable electronic health record will help educate patients and healthcare providers about radiation exposure, and could facilitate activities to minimize dose when possible," they wrote. "Understanding exposures to medical radiation delivered through actual clinical studies is a crucial first step toward developing reasonable strategies to minimize unnecessary exposures."
Commentary
An accompanying editorial questions why so many CT scans are being performed in the U.S.
There were an estimated 72 million CT scans conducted in 2007 alone, delivering radiation doses that were "eye opening," wrote Dr. Rita Redberg, a cardiovascular imaging specialist at UCSF and health policy advisor for healthcare giant Blue Cross/Blue Shield.
Citing an earlier study on the radiation delivered by CT scanning (Fazel et al, New England Journal of Medicine, August 27, 2009, Vol. 361:9, pp. 849-857), Redberg noted that "although most patients receive relatively low doses, nearly 20% of the study's population received 'moderate' exposures of between 3 and 20 mSv." Moreover, some 1.4 million patients received "high" doses of 20 mSv to 50 mSv, she added.
The two studies appearing today help answer the question of risks posed by CT and whether they are really justified, wrote Redberg, who has been criticized for her support of earlier efforts to restrict coronary CTA and virtual colonoscopy.
Smith-Bindman et al found a "13-fold variation between the highest and lowest does for each CT type studied," Redberg wrote. "There was no discernable pattern to the variation, which occurred within and across institutions. ... Even the median doses are four times higher than they are supposed to be, according to the current quoted radiation dose for these tests."
In the study by NCI researchers, CT scan use frequency in the U.S. was determined using several large databases. Excluding scans conducted after a diagnosis of cancer and those performed in the last five years of life, Berrington de Gonzales and colleagues projected 29,000 excess cancers as a result of the CT scans performed in2007, Redberg wrote.
"These cancers will appear in the next 20 to 30 years and by the authors' estimates, at a 50% mortality rate, will cause approximately 15,000 deaths annually," she wrote. "In light of these data, physicians (and their patients) cannot be complacent about the hazards of radiation or we risk creating a public health time bomb."
Redberg called for a multifaceted approach to radiation reduction beginning with a requirement that all institutions use the lowest-dose technique, considering that Berrington de Gonazales found that the "usual" protocol "sometimes unwittingly increased radiation." Redberg also called for reexamination of the paradigm that "more testing and more technology inevitably lead to better care."
Study conclusions criticized
In an e-mail to AuntMinnie.com, imaging advocate Dr. U. Joseph Schoepf, associate professor of radiology and medicine at the Medical University of South Carolina in Charleston, called the conclusions inherently flawed because they rely on atomic bomb survivor data and other unproven assumptions of risk.
"The healthcare reform debate is heating up on the Hill and the hordes brawling for the redistribution of our increasingly limited healthcare funds are coming out again," Schoepf wrote. "They are armed with pocket calculators and 50-year-old data on atomic bomb survivors. They claim 'known risks of radiation' and that 'the large doses of radiation from [CT] scans will translate, statistically, into additional cancers' creating a 'public health time bomb.'"
"Such statements are intended to create fear, but their line of logic breaks down due to the simple fact that a connection between radiation from medical imaging and cancer has never been established," Schoepf wrote. "On the contrary, while the numbers of medical imaging procedures are clearly on the rise, the mortality rates from cancer are dramatically dwindling in step."
According to a recent analysis by the U.S. National Bureau of Economic Research (Lichtenberg 2009), life expectancy increased more rapidly in states where the fraction of advanced diagnostic imaging procedures increased more rapidly, Schoepf wrote. "Such observations are conveniently ignored in this and related publications," he stated.
"Still, there are aspects to the current debate on radiation exposure that should give us pause," Schoepf wrote. "Overutilization of medical imaging unfortunately does occur; however, it is well recognized that this is not driven by radiologists, but by other medical specialties who perform imaging in their offices."
"There is indeed a need for greater transparency and involvement of the patient in the decision process that leads up to an imaging study," Schoepf continued. "However, this should not be pursued with the ulterior motive of scaring patients out of an indicated imaging test by raising the specter of radiation risk, but rather by explaining the expected benefits and discussing the current uncertainties surrounding radiation from medical imaging."
By Eric Barnes
AuntMinnie.com staff writer
December 14, 2009
hey, superc... and mr. sano...
superc, vese and another one have replied to my post with his name in it on the neph board...
mr. sano -- give me a moment and i'll get back to ya on your question...
cancer stats are based on computer modeling on survivers from hiroshima (this is the norm)... people in hiroshima were subjected to higher levels of radiation compared to the diagnostic range of radiation in CT scans... it's true, dose models are a linear non-threshold stochastic model which "measure" likelihood. which is why the creedo is ALARA, as low as reasonably achievable.
granted CT scans can have significant dosage... therefore, it is important to note that these are computer models predictions, there are no studies which show/point to cancers induced by CT scans... regardless, institutions should welcome the recommendations and manufacturers should continue inovating ideas to reduce dose.
bogdan1 please read my posts from last thursday til today... just click my moniker to find them...
or here
... http://investorshub.advfn.com/boards/profile.asp?user=169437
As far as strictly pps only, a comparable is NEPH.ob, look at them, they too have dropped in the past 5 trading days or so... likely, due to prolonged FDA clearance decision... similar to here... imo, i don't really see it more than anything but that...
NEPH.ob has not been waiting as long as we have but, it is somewhat similar... being that they resubmitted their response to the FDA in the Spring '09. and got a clearance for only 1 of their 3 510Ks -- but only two products essentially. one being a water filter and the other being a filter for hemodiafiltration. interestingly, if they approve/clear the latter, then it'll be a first going into the U.S. for a paradigm shift from hemodialysis treatment to hemodiafiltration treatments. many thought that would need a PMA (i.e., a class 3), or may be a class 2 to with clinicals (again, essentially the same).
thus, we wait for our 510k -- class 2 -- clearance as well.
meantime, what you have at the FDA this year is a change in administration and a change in location, yes the medical devices division moved during the summer time...
so, be this as it may/is... we wait... meanwhile traders do what they do...
i've got a little more dry powder to go toward either.
*****
then as someone else stated, as reading recent posts, could be a short attack on the CT data news... those buggers. or just people that don't really understand.
re: sykes, i wanted to report him to the SEC for making a false statement regarding something to the effect that the 510k was meaningless as the technology already exists when describing the DViS...
i asked him directly on yahoo more than once to ellaborate on that statement, he refused only to use the moment to plug his website...and name call.
my thinking was this: he falsely made this statement while materially attempting to manipulate/profit on it in a public forum thereby influencing others to his benefit...not only for his position but for his minions. it's there in black and white.
do you mean melissa davis? eom.
1st generation: short animation of
one other note, conventional radiophysics/health physics 'optimisation' teaches that one can not make the jump from incident x-ray photon to induced cancer... one never truly knows, at least in the realm of diagnostic radiation levels...
this is mainly from the studies on fruit flys, studies on ram testes provide us with information on cellular lifecycles which are radioresistant and radiosensitive...
this is why radiography (plain film) and fluoroscopy are considered viable approaches in medical care...
thus, these are interesting claims in the two articles and certainly worth a greater dissection of the methodology employed...
good news they ain't talkin bout us... and imho, i think GE/TOSHIBA ought to seriously consider aquiring us...
here's the editorial... now, you best make a point when you offer solutions...
"First, radiation protocols should be improved to eliminate the 13-fold difference in radiation dose for the same CT scan; exposures will be significantly reduced if all institutions were to use the lowest-dose technique. Smith-Bindman and colleagues3 found, for example, that the "usual" protocol sometimes unwittingly increased radiation. The authors offer several techniques to improve the quality of CT scans."
http://archinte.ama-assn.org/cgi/content/full/169/22/2049
now, here are the two articles:
1st:
Projected Cancer Risks From Computed Tomographic Scans Performed in the United States in 2007
Amy Berrington de González; Mahadevappa Mahesh; Kwang-Pyo Kim; Mythreyi Bhargavan; Rebecca Lewis; Fred Mettler; Charles Land
Arch Intern Med. 2009;169(22):2071-2077.
http://archinte.ama-assn.org/cgi/content/full/169/22/2071
Excerpt:
Reduction in risk could be achieved in a number of ways, including decreasing the number of unnecessary procedures as well as the dose per procedure. ***The American College of Radiology appropriateness criteria36 are an important tool for helping physicians to make the most appropriate imaging decisions for specific conditions, and widespread use of these criteria should reduce unnecessary CT scans.*** Mechanisms to evaluate appropriate dose levels, as well as guidance for reducing dosages, including reference levels for radiation dose,37 are available, and participation in radiation dose registries, such as the recently initiated American College of Radiology registry, can provide institutions with feedback on their radiation exposure levels in comparison with other institutions.38
2nd:
Radiation Dose Associated With Common Computed Tomography Examinations and the Associated Lifetime Attributable Risk of Cancer
Rebecca Smith-Bindman; Jafi Lipson; Ralph Marcus; Kwang-Pyo Kim; Mahadevappa Mahesh; Robert Gould; Amy Berrington de González; Diana L. Miglioretti
Arch Intern Med. 2009;169(22):2078-2086.
http://archinte.ama-assn.org/cgi/content/full/169/22/2078
Excerpt:
Consensus is growing that patients' exposure to radiation through medical imaging needs to be reduced, and we believe that 3 general approaches should be taken. First, CT examination protocols and techniques should be optimized and standardized to limit the radiation associated with individual scans. ***This would include standardizing protocols across sites, reducing multiple series within each examination, implementing dose reduction strategies, and encouraging participation in accreditation programs such as that offered by the American College of Radiology. In practice, these guidelines have not been widely embraced, perhaps because no regulatory component is associated with their use.*** ... A second approach to minimize medical radiation exposure should focus on reducing the number of CT examinations. Although difficult to fully assess, it has been reported that 30% or more of the CT examinations currently performed may be unnecessary. ... The third approach to reducing exposure may be to track and collect dose information at the patient level because patients may undergo repeated imaging over time.13
****
now, i want everyone to note one of the authors appearing in both articles...
Mahadevappa Mahesh
this is a very bright individual... i cited him in the current manuscript/paper on radiation exposure i have under evaluation for final acceptance to a journal...
also, he was the author of the article with which i used to get the picture of the 4th generation CT machine i posted about this weekend and today...
http://radiographics.rsna.org/content/22/4/949.full
importantly M MAHESH is the author of the paper i posted before when i was talking about method to minimize fluoroscopic dose...
http://radiographics.rsna.org/content/21/4/1033.full?sid=ec784f32-1207-4bb5-b155-faeb05344f8a
here's all of his articles from radiographics:
http://radiographics.rsna.org/search?author1=Mahadevappa+Mahesh&sortspec=date&submit=Submit
exactly and here just for fun... MRI versus chair...
this goes to show the strength of the [static] magnet...
yes, this is essentially a CT-gantry... of the 3rd generation...
both the x-ray source and the detector are spinning about the patient...
the x-ray beam is emitted from the source to the detector plate... because both spin the x-ray photons always strike the detector...
here's 3rd generation CT spinning up to max speed...
mr. sano, i want to first say thank you for asking this question... in order to best answer i thought it best to look again at the dominion footage...
http://imaging3.com/video_imaging3dominion.html
now, if i hadn't have done this i would be amiss, in my answer to you...
as my post on cone-beam CT states (as i posted over the weekend)...
i mentioned that (at least while reading the cone-beam physics tutorial article i mentioned, which is the last link which i included again here below)... that flat panel detector technology is the way to go...for cone-beam CT (CBCT) and i believe conventional CT machines may be attempting to go that way... (this latter comment i made based on the radiology article which goes along with the 4th generation picture from my post over the weekend)... it was sorta difficult to understand if they were implying that flat panel detectors are going to be used in conventional CTs or not... but they did seemed to imply an advantage for such...HOWEVER, FLAT PANELS ARE ABSOLUTELY NECESSARY FOR CONE-BEAM CT's because of beam geometries.
now, all this to say that:
again, for CBCT flat panel detectors are used... i just watched the dominion footage per link above... i had previously thought that this footage had the gantry components spinning at working speed and thus it was difficult to ascertain componentry to show the insides. however, this is not the case, and actually dean is pointing to the flat panel detector in the DViS during the clip....
now, comes specificity: he calls the detector a CCD detector... which is technically what it is...
you'll note that his bio states, "He was responsible for integrating a CCD camera with a mobile fluoroscopy into the C-arm, a system that is used throughout the medical diagnostic medical imaging industry today."
http://imaging3.com/management.html
NOW MORE THAN THIS ABOVE: READ THIS BELOW:
In early 1994, Imaging3 began offering upgrades for OEC C-arms. The most successful upgrade was a CCD (Charged Coupled Device) camera, which improved image quality of older systems comparable with that of brand new products. ***This offering became so successful that the Company integrated this upgrade with used OEC C-arms and built custom units for NASA, Harvard, University of California at Irvine, University of California at Davis, Baylor University, Baxter Healthcare and other prestigious healthcare organizations. Later that year, Imaging3 applied for and received United States Food and Drug Administration ("FDA") approval for this device described as the NASA II CCD C-arm.***
http://msnmoney.brand.edgar-online.com/DisplayFilingInfo.aspx?TabIndex=2&FilingID=6508150&companyid=385706&ppu=%252fDefault.aspx%253fticker%253dimgg
Thus...
this is why i've stated that dean is the rarest of the biomedical engineers...
the entrepreneurial (the rarest), but is his a fine combination of the two types: the researcher and the clinical...
*****
okay now, to get to the rest of your question...
the cone-beam CT uses a CONE-BEAM it is an x-ray beam sent out having CONIC geometries...
typical/conventional CT use a FAN-BEAM...think what a chinese fan looks like... look again at Figure 2 to compare the two beam types...
http://www.ajnr.org/cgi/reprint/30/6/1088?maxtoshow=&HITS=60&hits=60&RESULTFORMAT=&fulltext=three+dimensional+fluoroscopy&andorexactfulltext=and&searchid=1&FIRSTINDEX=0&sortspec=relevance&resourcetype=HWCIT
*****
And finally, to get back to your question... thus, the DViS is more or less a 3rd generation CT gantry... albeit using a CCD detector... all other detectors for conventional 3rd generation CTs do not use a flat panel at this time. the detector is specific piece of equipment and is concave to form snuggly inside the gantry curvature... HOWEVER, AGAIN I'M NOT SURE IF MANUFACTURERS ARE ATTEMPTING TO GO THE FLAT PANEL ROUTE FOR THEIR CONVENTIONAL CT's (per that radiology article)...
a 4th generation gantry will have the detectors "embedded" in the actual gantry inside... only the x-ray source does the spinning... the beam hits the inside curvature (embedded detectors) of the gantry... THIS IS THE TYPE WHICH HASN'T REALLY CAUGHT ON... more or less, a "failed" generation...
*****
actually, i should've known all this b4 now, and sonomawest... this post is actually for you too, as you had asked something sorta similar before about detectors, photography, and radiography, etc.