CT scans linked to brain cancer, leukemia in children

Children who receive CT scans have almost three times the risk of developing leukemia and brain cancer later in life, a study has found. The study, in Lancet, assures parents that the risk of getting brain cancer or leukemia is still very low, even when the risk is tripled.

Nevertheless, the researchers warn that doctors should only give CT scans to children when the procedure is absolutely necessary.

CT scans were introduced in the 1970s. An estimated 72 million CT scans were performed in the US in 2007, and the benefits of CT scans usually outweigh the risks, the Guardian reported.

"This study will push us to be even more circumspect about using [CT scans]," Dr. Mark Pearce, an epidemiologist from Newcastle University, told the BBC. 

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The researchers looked at 180,000 patients who had received CT scans when they were children. The researchers found that for children under the age of 10 who had received head scans, there was just one extra case of leukemia and one extra brain tumor per 10,000 patients, the Guardian reported.

However, leukemia and brain cancer are also the most common types of childhood cancers, according to the National Cancer Institute, and the overall incidence of both types of cancer have increased since the 1970s. 

While various types of radiation exposure have long been linked to cancer risk, (such as radiation from a nuclear disaster or radiation therapy) this is the first study to find direct evidence of a link between radiation exposure from the CT scans and cancer, MSNBC reported.