Initiatives Focus on Limiting Radiation Exposure to Patients During CT Scans

IN THE PAST DECADE OR SO, EMERGING data have raised concerns about increased cancer risk attributable to the radiation doses experienced by patients who undergo computed tomographic (CT) scanning. More than 80 million CT scans are performed annually in the United States. Limiting radiation exposure is a consideration for anyone, but the concern is heightened for children, who undergo about 6 million CT scans per year, according to the American College of Radiology (ACR). Children are growing, their tissues may be more radiosensitive, and their smaller size makes them more vulnerable if dosing is not adjusted accordingly. In addition, compared with adults, children who undergo a CT scan typically have many more years of life ahead of them and thus have a wider window of opportunity for the manifestation of radiation injury. One of the first reports on estimated risks of fatal cancer resulting from pediatric CT radiation exposure, by David Brenner, PhD, DSc, director of the Center for Radiological Research at ColumbiaUniversityMedicalCenterinNewYork City,andcolleagues,estimatedriskusing doses derived from studies of those exposedtoatomicbombsinJapan(Brenner DJ et al. AJR Am J Roentgenol. 2001;176: 289-296).Lastyear, researchersreported evidence of a relationship between leukemia incidence and estimated CT scan radiation doses to bone marrow during childhood, as well as between brain tumor incidenceandestimatedCTscanradiation doses to the brain (Pearce MS et al. Lancet. 2012;380[9840]:499-505).