An analysis of seven healthcare systems in the U.S. has found that pediatric radiation exposure from CT scans can potentially double the risk of cancer caused by radiation.

The study, published in the journal JAMA Pediatrics, revealed that the number of CT scans among young children has more than doubled from 1996 to 2005. Scans rose from about 330,000 in 1995 to 1.65 million in 2008, a five-fold increase, indicating that over the past several years the use of CT scans in pediatrics has shot up.

CT scanning produces multiple images or pictures of the inside of the body.

CT scans of internal organs, bones, soft tissue and blood vessels are clearer and provide more details than regular x-ray exams.

An explanation of a CT scan by Andrey Lindegrin, Senior Radiographer at The London Clinic

What’s worrying is that the levels of radiation that CT scans emit are much higher than conventional radiography and have been associated with a higher risk of cancer. Children are more sensitive to the radiation.

The authors wrote in the study background that children have a whole lifetime ahead of them for cancer to develop.

They noted that “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 team of researchers, led by Diana L. Miglioretti, Ph.D., of the Group Health Research Institute and University of California, Davis, gathered data from seven different health care systems to determine whether the use of CT scans in pediatrics increases cancer risk.

Between 1996 and 2005 CT use doubled in children younger than 5 and tripled among children between 5 and 14 years of age.

According to the results of the study, people at the highest rise of developing solid cancer were female younger patients as well as those who received CT scans of the abdomen/pelvis or spine.

Among girls the researchers estimated that one solid cancer was caused for every 300 to 390 abdomen/pelvis scans, 330 to 480 chest scans, and 270 to 800 spine scans.

Leukemia risk was highest among head scans for children under 5 (a rate of 1.9 cases per 10,000CT scans).

US Navy 060510-N-3532C-008 The Computerized Tomography (CT) scan machine aboard the Military Sealift Command hospital ship USNS Mercy (T-AH 19) uses x-rays and computers to create cross-sections of bodily tissues
Pediatric CT scans could be responsible for an estimated 4,870 future cancers every year.
The authors of the study concluded:

“Thus, more research is urgently needed to determine when CT in pediatrics can lead to improved health outcomes and whether other imaging methods (or no imaging) could be as effective.

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.”

Surprisingly, according to a previous study published in the journal Radiology, most radiologists who conduct and interpret CT examinations of children do not have the necessary training in pediatric radiology.

In addition, a few years ago an estimated3.2 percent of cancer cases in Japan were caused by exposure to radiation during CT scans at hospitals.

Written by Joseph Nordqvist