Exposure to CT Scan Radiation in Childhood Increases Risk of Cancer in Adulthood

A new study provides evidence highlighting the hidden risks of being exposed to computed tomography (CT) scan at a young age - it can increase the risk of developing cancer later in life.

Researchers Diana L. Miglioretti and colleagues from the Group Health Research Institute and University of California analyzed data collected from seven U.S. health care systems and found that the number of children aged below 14 years who took CT scans of the head, abdomen, pelvis, chest or spine had gone up considerably between 1996 and 2005.

During the study period, CT scan among children aged below 5 nearly doubled, and those aged between 5 and 14 tripled. At the end of the study, children who were exposed to ionizing radiation were found to have higher risks of developing cancer than adults who had CT scans.

The study, published in the journal JAMA Pediatrics, also noticed that the exposure to radiation affected young children more than older ones, and girls more than boys.  Undergoing CT scans related to the abdomen/pelvis or spine had greater risks of cancer compared to other parts of the body.

According to the researchers, children are more sensitive to "radiation-induced carcinogenesis", and avoiding unnecessary CT scans among children can prevent about 5,000 cases of cancer every year in the country.

"The increased use of CT in pediatrics, combined with the wide variability in radiation doses, has resulted in many children receiving a high-dose examination," the authors wrote in a news release.

"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," they added.

Many studies have proved that excess use of CT poses a health concern for children. A study published in The Lancet earlier found that children exposed to radiation during multiple CT scans were at a higher risk of developing brain cancer and leukemia later in life. The study also found the radiation dose of a single CT scan 10 times higher than a normal X-ray procedure.

Another study from Australia found that children who were exposed to CT scans had a 24 percent higher risk of developing cancer later, and the risks increased by 16 percent with every additional scan.