Risks and Realities of Radiation Dose in Medical Imaging
W Hendee*, C McCollough*, M O'Connor*, Mayo Clinic, Rochester, MNTU-G-213CD-1 Tuesday 4:30:00 PM - 6:00:00 PM Room: 213CD
Several publications over the past few years have predicted thousands of cancers and cancer deaths in the US population caused by radiation exposures from medical imaging. The predictions are derived from risk estimates in the National Academy of Sciences BEIR VII report. These risk estimates are highly speculative with wide confidence intervals, and the BEIR VII committee has warned against using them to estimate cancer risks to individuals or populations. They are based on risk models derived from the linear no-threshold hypothesis of radiation risk at low doses, a hypothesis that has been challenged by experiments at the cellular and animal levels as well as by data of cancer incidence in medically-, occupationally-, and environmentally-exposed individuals. The main source of data for the BEIR VII risk estimates are the survivors of the Japanese A-bomb explosions, a population greatly different from the US population that was exposed to radiation conditions greatly different from those of medical imaging. Collectively, the uncertainties in the derivation of the BEIR VII risk estimates, and the intrinsic speculative nature of the risk estimates themselves, cause predictions of cancers and cancer deaths to be more hypothetical than real in populations exposed to medical imaging. Unfortunately, these hypothetical predictions are themselves a health risk, because they create anxiety in patients resulting in a reluctance to undergo medical imaging procedures prescribed for their benefit.