The increased use of CT examinations in pediatrics is raising concerns about cancer risk from exposure to ionizing radiation. A study has been carried out to quantitate the increase in the use of CT scans in children younger than 14 years of age and to evaluate the potential increase in risk of cancer. (Miglioretti et al. JAMA Pediatrics 2013; 167: 700). Dr DL Miglioretti of the Group Health Research Institute and University of California, Davis, and colleagues quantified trends in the use of CT in pediatrics plus the associated radiation exposure and estimated potential cancer risk using data from seven U.S. health care systems. 
The authors noted that the use of CT doubled for children younger than 5 years old and tripled for children 5 to 14 years of age between 1996 and 2005 before remaining stable between 2006 and 2007 and then beginning to decline. The projected lifetime attributable risks of solid cancer were higher for younger patients and girls. The risks were also higher for patients who underwent CT scans of the abdomen/pelvis or spine than for patients who underwent other types of CT scans. The estimates also suggest that for girls, a radiation-induced solid cancer is projected to potentially result from every 300 to 390 abdomen/pelvis scans, 330 to 480 chest scans, and 270 to 800 spine scans, depending on age. The potential risk of leukemia was highest from head scans for children younger than 5 years of age at a rate of 1.9 cases per 10 000 CT scans. Based on their calculations, the authors also suggest that reducing the highest 25 percent of doses to the median (midpoint) may prevent 43 percent of these cancers. “Thus, more research is urgently needed to determine when CT in pediatrics can lead to improved health outcomes and whether other imaging methods (or no imaging) could be as effective. For now, it is important for both the referring physician and the radiologist to consider whether the risks of CT exceed the diagnostic value it provides over other tests, based on current evidence”.
