What Do We Really Know About Cancer Risks At Doses Pertinent To Ct Scans

There has been increasing use of CT scans globally. This increased use is not in itself of concern, and largely reflects the remarkable clinical benefits of CT. Inappropriate use of CT is, however, of concern, particularly as the potential for carcinogenic effects is yet to be fully understood. The first major media attention to cancer risk from CT scan arose from a series of papers and an Editorial published in AJR in 2001. This was followed by another series of papers in 2007 and associated media attention to the estimation of the number of cancer deaths that may occur in US as a result of radiation exposure from CT. In recent years there have been a series of papers and position statements suggesting that these predictions need to be worded very carefully. This is because they may lead to sensationalistic articles in the public media that might cause some patients and parents to refuse medical imaging procedures, placing them at substantial risk by not receiving the clinical benefits of the prescribed imaging. There is a considerable body of work within the field of cognitive psychology that indicates that a discussion of risk may lead to bias in how parents would interpret information and potentially refuse indicated examinations. It follows that discussion of any potential risk of imaging should be accompanied by a discussion of the corresponding benefit of imaging or the harm if imaging is not done. Studies reported in the literature both for CT scans and for fluoroscopy suggest that when this is done, patients or parents do not refuse needed imaging.Learning Objectives:1. To understand the global usage of diagnostic x-rays and CT and issues and approaches for safety2. To learn about science behind current dose effects relationship and risk estimates at the level of few CT scans and the uncertainties in estimating risks from CT scans3. To understand how issues of CT scan risks are perceived by patients and physicians and how they can be better presented to them