Safety Corner, v2.1
Radiation Risk vs. Benefit and Study Appropriateness
The issue of radiation risks in radiology continues to be debated in the medical imaging community. Because patients and operators are exposed to ionizing radiation, which have increased population doses from medical imaging in the United States by 600% in one generation, this debate is of obvious importance. The current arguments focus on the issue of whether radiation risks to patients and operators in medical imaging are real. In the absence of a consensus on the science of radiation risks, the imaging community needs to develop radiation protection policies and agree about how these policies are to be applied in clinical practice. In this article, what is currently known about radiologic risks is reviewed, policies that should be adopted based on our current knowledge are proposed, and how these policies can be applied to adequately protect patients in everyday clinical practice is described.
One important consequence of assuming that radiation risks are real is that any patient exposure in a radiologic examination must be justified. This principle—which requires patient benefits to exceed all risks including radiation—is well established in radiation protection, including medical practice. Identification of justified medical imaging examinations is the responsibility of individuals who are knowledgeable about the most appropriate examinations for a clinical indication, the diagnostic information that is likely to be generated, and the corresponding patient radiation doses and associated risks. American Board of Radiology–certified radiologists, for example, are trained to identify which examinations are appropriate, what kind of diagnostic information might be obtained, and the corresponding patient doses and risks. Knowledgeable individuals know whether they would proceed with a given examination for any clinical indication for a close family member, a very good sign that an examination is truly worthwhile.
Radiologists must be knowledgeable about radiation risks to be able to help patients who have questions regarding planned CT examinations for themselves or for their children. For indicated and questionable examinations, the emphasis should not be on the existence of any radiation risks, but rather on whether a planned examination is worthwhile. Understanding whether a radiologic examination is worthwhile requires a mastery of what is known about risks by the radiologist and of the corresponding uncertainties. Thus, a mastery of radiation risks helps imaging practitioners to be respectful of ionizing radiation and to avoid the extremes of being either too fearful or too blasé about these risks.
Radiation protection in medical imaging can be reduced to two simple principles that are easy to understand, straightforward to implement, and likely to be acceptable to most medical imaging practitioners: Patient examinations need to be justified by a net patient benefit, and unnecessary radiation should be eliminated (i.e., ALARA). Current radiation risks estimates, however, are relatively small. All activities in life (e.g., driving automobiles) are associated with risks, and medical imaging is no different, so the most important message to convey to patients is whether a proposed examination is worthwhile. Our collective goal should be ensuring all radiologic examinations are justified and are ALARA, which maximizes the benefits of medical imaging for our patients.
American Journal of Roentgenology 204 January 2015 Walter Huda pages 124-126