Children who get two or three CT scans have a higher risk of developing brain cancer and leukemia later in life. That's according to a study published Wednesday in the Lancet, which stresses that the risk is still small and likely outweighed by the need to get the test. Researchers studied nearly 180,000 patients under age 22 who had a CT scan between 1985 and 2002.
They found that 74 of them were diagnosed with leukemia, while 135 had brain tumors. As few as two CT scans of the head in childhood can triple the risk of developing brain tumors, according to the study, while five to 10 of these scans can triple the risk of leukemia.
CT scanning allows doctors to look inside the body more accurately than conventional X-rays, but provides a higher dose of radiation. "If you need a CT scan, get one," health physicist Owen Hoffman, of the consulting firm SENES Oak Ridge, in Oak Ridge, Tenn., told U.S. News. "This doesn't mean that you're going to come down with cancer.
The added information from a CT scan far outweighs the cancer risk. But the risk is there, and it's such that you should ask your doctor, 'Do I need the scan?' The doctor should have the information to reassure a patient that the scan is really necessary."