Unnecessary CT Scans Increase Children's Risk for Cancer

Researchers believe that reducing the number of unnecessary and high-dose CT scans that children undergo could potentially cut their lifetime risk for associated cancers by as much as 62 percent, according to a recent study. CT scans use a series of dozens of x-rays from different positions to yield a 3D image of organs and bones.

U.S. News and World Report writes that researchers found that out of 4 million CT scans of the most commonly imaged organs conducted in children throughout the United States annually, 4,900 of those scans resulted in future cancers.

Researchers also found that reducing the highest 25 percent of radiation doses could prevent nearly 2,100 (43 percent) of future cancers. Naturally, eliminating unnecessary CT scans that could potentially lead to a higher number of cancers is important too.

"There are potential harms from CT, meaning that there is a cancer risk -- albeit very small in individual children -- so it's important to reduce this risk in two ways," study lead author Diana Miglioretti, a professor of biostatistics in the department of public health sciences at the UC Davis Health System, in California, said in a health system news release. "The first is to only do a CT when it's medically necessary, and use alternative imaging when possible," she said. "The second is to dose CT appropriately for children."

The researchers examined data regarding the use of CT in children at various health care systems across the United States between 1996 and 2010. For children five and under, CT use nearly doubled from 11 per 1,000 in 1996 to 20 per 1,000 between 2005 and 2007. However, statistics show that the numbers fluctuated again, with a decrease to 16 per 1,000 in 2010.

For children ages 5 to 14, CT use was even worse. It nearly tripled from 10.5 percent per 1,000 in 1996 to its peak of 27 per 1,000 in 2005. However, since then, it's fallen to 24 per 1,000 in 2010.

Researchers examined areas of the body that would be at the highest risks for cancer from CT scans, including the head, abdomen/pelvis, chest and spine. These areas of the body account for more than 95 percent of all CT scans, according to the researchers.

The study was published online June 10 in the journal JAMA Pediatrics.