The study authors emphasized that health care providers are already cautious in their use of X-rays in children, and use them only when necessary to diagnose potential problems such as respiratory illnesses, broken bones and fractures.
"X-rays are a valuable tool, and our findings indicate that their use should continue to be judicious," said Karen Bartley, doctoral student in epidemiology and first author of the study. "Of greater concern, perhaps, is the use of newer imaging technologies, which are becoming more common and which produce far higher doses of radiation."
Computed tomography (CT) scans, for instance, produce a 3-D image by compiling together multiple "slices" of 2-D images that were taken as the scanner moved along. A 2009 study from the National Cancer Institute projected that the 72 million CT scans received by Americans in 2007 would lead to 29,000 excess cancers. The number of scans in the United States has increased over recent decades, going from 3 million scans in 1980 to more than 70 million a year today.
"The findings about increased leukemia risk certainly warrant further investigation," said UC San Francisco radiologist Dr. Rebecca Smith-Bindman, who was not part of the X-ray study. "If even plain film X-rays are associated with an increased risk of leukemia, then one has to wonder about CT scans, some of which can generate 500 times the dose of radiation of an X-ray."
Dr. Smith-Bindman is in the process of characterizing the ionizing radiation exposure to children from CT scans as part of a study funded by the National Cancer Institute. She noted that two-thirds of the imaging procedures children undergo are conventional X-rays, accounting for about 20 percent of their exposure to radiation from medical imaging. In contrast, CT scans make up only 10 pe
|Contact: Sarah Yang|
University of California -- Berkeley