In Reply We appreciate Dr Jha’s thoughtful response to our article.1 We agree that there is significant uncertainty and disagreement among experts about estimating the exact cancer risk associated with the ionizing radiation from computed tomographic (CT) imaging; informing patients about this uncertainty is a difficult task.
However, the case for an increased incidence of cancer among those exposed to the levels of radiation found in typical CT scans does not rely on modeling, as Jha suggests. Recent large-scale epidemiologic studies have quantified a small but seemingly real and dose-dependent cancer risk associated with CT scans among children and adolescents after only 10 years of follow-up.2,3 This evidence adds to earlier epidemiologic evidence that identified an increased incidence of cancer among atomic bomb survivors of all ages whose mean level of exposure to ionizing radiation was equivalent to 2 to 3 CT scans.4
Caverly TJ, Prochazka AV, Stickrath C. Do Physicians Have an Obligation to Disclose the Uncertainty About Harms or Just the Harms?—Reply. JAMA Intern Med. 2013;173(18):1752. doi:10.1001/jamainternmed.2013.8462