 most frequently performed, including abdomen and pelvis, chest and head exams.
It's estimated that two-thirds of the projected cancers will occur in women, primarily because of the higher frequency of use in women (60 percent) and because of higher breast and lung cancer risks from scans that expose the chest.
While the numbers may be scary, Berrington de Gonzalez said people should realize "that CT scans provide great medical benefits and that, in general, individual risks are small and should be outweighed by the benefits if the CT scan is clinically justified."
To ensure safe use, the authors' recommendations focus on reducing radiation dosages, eliminating unnecessary and repeat examinations, and creating searchable electronic medical records to collect and track CT studies over time.
"Although there is much work to be done, at this point this should be the agenda in radiology quality improvement programs," said Dr. Richard T. Griffey, associate chief for quality and safety in the Division of Emergency Medicine at Barnes-Jewish Hospital and an assistant professor at Washington University School of Medicine in St. Louis.
Clinicians also need more information about patients' radiation exposures over time, he added. "We have what can be a very fractionated health-care system, and doctors may not know what studies their patients have undergone in their own institution, let alone others, over their lifetime," he said. "While the incremental harm of a single study may be impossible to really know, some sense for cumulative radiation exposure would be valuable."
SOURCES: Rebecca Smith-Bindman, M.D., professor, residence, radiology, University of California, San Francisco; Amy Berrington de Gonzalez, Ph.D., investigator, Radiation Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Md.; Andrew J. Einstein, M.D., Ph.D., assistant professor, clinical medicine, and director, cardiac computed tomography research, Columbia University College of Physicians and Surgeons, New York City; Richard T. Griffey, M.D., associate chief, quality and safety, Division of Emergency Medicine, Barnes-Jewish Hospital, and assistant professor, Washington University School of Medicine, St. Louis; Dec. 14/28, 2009, Archives of Internal Medicine