Replies to post #176892 on Vivos Inc (RDGL)

[chereb19]

Direct Interstitial Injection: An Approach to Optimizing Therapeutic Ratios for Safe and Effective Delivery of High-dose Radionuclide Therapy in Treating Solid Tumors (P446)
Mon, July 08
Gatlin C/D
Poster Session

Part of:
Poster Session 1
Info
Abstract Text:
The limiting constraint in all modes of radiation therapy is unwanted dose to non-target normal organs and tissues, which can cause severe side-effects. An ideal radionuclide therapy places 100% of the treatment dose uniformly within the clinical target volume without radionuclide out-migration from the tumor. Such treatment can be achieved by employing an optimum radionuclide and chemical form with carrier properties that facilitate injection, placement, and in-tumor retention. An optimized radiation dose achieves effective tumor destruction while preventing or minimizing normal tissue adverse reactions. Yttrium-90 emits no gamma rays and can be handled safely with negligible dose to workers, patients, and family members. Methods: Yttrium-90 was prepared as insoluble (yttrium phosphate) microparticles in a phosphate-buffered saline (PBS) solution mixed with a polymer composite (hydrogel) carrier for direct intra-tumoral injection. Privately owned cats, dogs, and horses presenting with soft-tissue sarcomas were treated at several veterinary clinics to demonstrate safety, best placement methods, and most effective treatment doses. Results: Upon injection using multiple parallel-needles, the carrier solution warmed and gelled in situ--forming a solid matrix that entrapped the Y-90 microparticles and prevented out-migration via blood circulation. Co-registered PET/CT imaging post-injection confirmed uniform placement in target tissues. Each subject exhibited an objective response to therapy; best results were associated with smaller tumors treated at higher doses (300 to 400 Gy). Treated animals experienced no radiation-related illness or adverse tissue reactions. Therapeutic ratios achieved ranged from 200:1 upwards to 10000:1. Complete tumor destruction was confirmed by histopathology. Conclusions: Some tumors represent poor candidates for surgical excision or cannot be treated using external beams for curative therapy. However, direct intra-tumoral injection of Y-90-microparticles in a polymer composite matrix provides a safe, efficient, high-dose therapy, with tumor cell killing associated with localized dose. Results of this research confirm the opportunity for multiple oncology applications in both human and veterinary patients.



Keywords:
radionuclide therapy cancer treatment yttrium-90

Session Topic:
MA5: Radiation Protection in Healthcare

Authors
Darrell R. Fisher, Ph.D.
Versant Medical Physics and Radiation Safety
Michael K. Korenko

[kayak_wench]

Fisher is a true scientist and researcher. He has fully retired from his career position but can't stop working and seems to be spending his retirement working as a consultant. Just since 2023 he has been a co-author on four respected journals and penned a published opinion for Heath Physics. (Go to Google Scholar and search on 'Darrel R. Fisher'). His name has such clout that someone will likely have him peripherally involved in their research just so they can include him on as a co-author which is confirmation that someone as respected and knowledgable as him supports their work. Only the best of the best in a field get to the point that they churn out journal articles like this. Vivos having Fisher standing behind Radiogel and Isopet is a real asset.

At this year's IRPA he just presented a poster, but it does represent very recent results so it is valuable information (abstract below). As an aside he also taught a course on Sunday "Fundamental Principles of Medical Internal Radiation Dosimetry". In the description of the course they describe him as "Your instructor has more than 40 years of relevant experience in clinical radiopharmaceutical dosimetry and patient case studies, including 30 years as a member of the MIRD Committee of the Society of Nuclear Medicine and Molecular Imaging."

Abstract of poster he presented on Monday. I put in bold the items that largely put to rest my concerns in the recent X post. Dr. Fisher really doesn't care about Radiogel/Isopet what he cares about is radiation safety and clinical studies (as the google scholar search shows by how many technologies and areas he is involved). So again his stamp approval really matters as no one is going to believe he is a paid shill for a small biotech company.

Direct Interstitial Injection: An Approach to Optimizing Therapeutic Ratios for Safe and Effective Delivery of High-dose Radionuclide Therapy in Treating Solid Tumors (P446)
The limiting constraint in all modes of radiation therapy is unwanted dose to non-target normal organs and tissues, which can cause severe side-effects. An ideal radionuclide therapy places 100% of the treatment dose uniformly within the clinical target volume without radionuclide out-migration from the tumor. Such treatment can be achieved by employing an optimum radionuclide and chemical form with carrier properties that facilitate injection, placement, and in-tumor retention. An optimized radiation dose achieves effective tumor destruction while preventing or minimizing normal tissue adverse reactions. Yttrium-90 emits no gamma rays and can be handled safely with negligible dose to workers, patients, and family members. Methods: Yttrium-90 was prepared as insoluble (yttrium phosphate) microparticles in a phosphate-buffered saline (PBS) solution mixed with a polymer composite (hydrogel) carrier for direct intra-tumoral injection. Privately owned cats, dogs, and horses presenting with soft-tissue sarcomas were treated at several veterinary clinics to demonstrate safety, best placement methods, and most effective treatment doses. Results: Upon injection using multiple parallel-needles, the carrier solution warmed and gelled in situ--forming a solid matrix that entrapped the Y-90 microparticles and prevented out-migration via blood circulation . Co-registered PET/CT imaging post-injection confirmed uniform placement in target tissues . Each subject exhibited an objective response to therapy; best results were associated with smaller tumors treated at higher doses (300 to 400 Gy). Treated animals experienced no radiation-related illness or adverse tissue reactions. Therapeutic ratios achieved ranged from 200:1 upwards to 10000:1. Complete tumor destruction was confirmed by histopathology. Conclusions: Some tumors represent poor candidates for surgical excision or cannot be treated using external beams for curative therapy. However, direct intra-tumoral injection of Y-90-microparticles in a polymer composite matrix provides a safe, efficient, high-dose therapy, with tumor cell killing associated with localized dose. Results of this research confirm the opportunity for multiple oncology applications in both human and veterinary patients.