CT Scans for Children May Increase Risk of Cancer: Study

Repeated CT scans could triple a child’s risk of developing cancer, according to the findings of a new study. 

When a child receives numerous radiation doses form CT scans, they may face an increased risk of brain cancer, leukemia and cancers of the blood and bones, according to the findings of research published this week in the medical journal The Lancet.

Children are more sensitive to radioactivity than adults, according to the researchers from the U.S., Canada and Britain. However, doctors can take steps to limit exposure and the number of scans, they said.

The researchers conducted a retrospective cohort study involving nearly 180,000 patients under the age of 22 in Britain between 1985 and 2002. They found that those who received a cumulative dose of 30 milliGrays (mGy) or more of radiation had three times the risk of brain cancer and leukemia when compared to those with only a cumulative dose of 5 mGy. Receiving 50 to 74 mGy tripled the risk of brain tumors.

Of the patients studied, 74 were diagnosed with leukemia and 135 with brain tumors.

Doctors need to use CT scans wisely, the researchers concluded. Different methods of obtaining the data should be explored, but if there is a medical reason for a CT scan and no other method of obtaining that information is available then the benefits of the scan still outweigh the risks, the researchers noted.

Last month the FDA issued new guidance on how to protect children from excessive radiation exposure. The agency wants manufacturers to prove that their X-ray imaging devices are safe and effective for use on children before allowing them onto the market, and has proposed to label any devices that fail to provide such proof as potentially hazardous to children. The guidance is in draft form and is awaiting finalization.

In November 2010, the FDA recommended that the radiation therapy industry make changes to equipment and training to lessen the risk of radiation overdose for patients. The recommendations came after a year-long investigation by the FDA which concluded that nearly all radiation exposure problems suffered by patients are due to operator error and are rarely contributed to by broken CT scanners.

CT scan procedures and other forms of radiation therapy across the country came under close scrutiny prior to the recommendations by the FDA after the discovery that a number of patients have suffered radiation overexposure from CT Scans performed incorrectly.