Children, Computed Tomography Radiation Dose, and the As Low As Reasonably Achievable (ALARA) Concept

It is apparent that without extrapolation or animal experimentation, low-dose radiation has a small but statistically significant individual risk of excessive cancer over a child’s lifetime.1–3 This data was recently published as part of the ongoing, >50-year study of the survivors of the atomic bomb that cost $500 million. The kind of radiation and doses these individuals were exposed to is similar to that from computed tomography (CT) (Fig 1). The total body effect of the A-bomb versus the more localized effect of medical radiation makes little difference on the outcome. Figure 2 is an explanation of terminology of the radiation doses used. There is clearly an overlap between the CT doses currently used and the low doses that the atomic bomb survivors received. Fig 1. Relevant dose range for pediatric CT: 6 to 100 mSv (0.006–0.1 Sv). From Brenner DJ. Estimating cancer risks from pediatric CT: going from the qualitative to the …