Biotech Values

[bobrmd]

The incidence of cancers induced by diagnostic radiaton is a controversial subject because there is no good data for lower doses of radiation. Most of the estimates for lower doses of radiation such as a ct scan or chest xray are extrapolated from higher doses assuming either a linear quadratic or linear model.

Practically speaking, we estimate the risk benfit ratio. The risk for a single ct for virtual colonoscopy is extremely low perhaps 1/10000 to 1/100000. There is no real good data. The risk of cancer also varies with the part of the body that is exposed and the age you are when exposed to radiation.

We generally dont even tell patients the risk because it is so low and if a patient does develop a cancer later on there is no way to prove cause and effect. We can only look at retrospective data of large populations that were exposed.

Yes, the dose from a ct is much more than a chest xray.