Are Children Being Exposed to Too Much Radiation?

January 5, 2011

Although imaging tests a critical component of quality medical care, some are beginning to question where the line should be drawn when it comes to kids.

A new study shows children frequently undergo diagnostic imaging procedures during their routine clinical care—a trend that has led to widespread concern about radiation exposure and the potential for future cancer risk.

“Our findings indicate that more awareness about the frequent use of these tests may be needed among care providers, hospitals and parents,” said Adam L. Dorfman, MD, of the University of Michigan Medical School, in a press release. “Imaging tests are a critical component of good medical care, but the high number of tests raises questions about whether we are being judicious in our use of the technology.”

Despite widespread discussions about the health hazards of environmental exposures in children, radiation exposure from the frequent use of imaging procedures has received less attention, possibly due to limited contemporary data in younger patients.

The study, which is published in the Archives of Pediatrics and Adolescent Medicine, identified 355,088 children under the age of 18 in five large US health care markets to track how often these imaging procedures are used. Dorfman and colleagues found that over 400,000 imaging procedures were performed in just three years, with 42.5% of the children receiving at least one of these procedures and many undergoing multiple tests. The types of tests included everything from routine x-rays that use very low doses of radiation to more advanced tests, like CT scans. Based on these data, the average child in this study population would be expected to receive approximately seven imaging procedures utilizing radiation by age 18.

Among the tests that the investigators considered, CT scans are the most important from the standpoint of radiation exposure. Nearly 8% of the children in the study received a CT scan in the three-year study period, with 3.5% of the children receiving more than one. Understanding patterns of utilization of these tests in children is critical because children and infants are more susceptible than adults to the risks of radiation exposure, according the authors.

“Developing tissues in children are more sensitive to radiation and their longer expected life spans also allows additional time for the emergence of detrimental effects,” said co-author, Reza Fazel, MD, MSc, of Emory School of Medicine. Fazel cautions that for any individual child undergoing a single test the risk is typically low.

“Of course, there is immense life-saving value in medical imaging, so our study doesn’t suggest at all that these tests shouldn’t be used in children,” added co-author Kimberly E. Applegate, MD, of Emory University. “We have to be smarter about how we use tests. For example, children don’t always need the same radiation dose during a CT scan to get the same quality of image and information.”

Investigators note that each imaging procedure should be guided by the principle of ALARA (As Low As Reasonably Achievable), which advocates for minimizing radiation doses while still obtaining sufficient clinical information.