A new study reveals that CT scans raise the risk for cancer in children later an life, an issue on which we have long been writing.
The study, conducted by international researchers, found that children who received several CT scans have increased risks for brain cancer and leukemia later in their lives, said the Associated Press (AP). The researchers said the risk is small and likely does not outweigh the need for testing.
The team studied 180,000 patients under the age of 22 who received a CT scan in British hospitals between 1985 and 2002; patients were followed until 2008. According to the AP, 74 patients were diagnosed with leukemia and 135 were diagnosed with brain tumors. Most scans were of the head and data measured radiation doses—not the number of scans—said the AP, explaining that the amount of radiation delivered to the brain, and bone marrow, for instance, is dependent on patient age and size.
“CT scans are very useful, but they also have relatively high doses of radiation, when compared to X-rays,” said Mark Pearce of Newcastle University, the study’s lead author. Pearce conceded that CT scans were generally warranted; however, more work is needed to reduce radiation, said the AP. The team concluded that brain tumor risks tripled in children who underwent three scans and leukemia risks tripled with 5-10 scans. The risk for leukemia in children is 1 in 2,000; having several CT scans increases that risk to 1 in 600.
The team pointed out that today’s CT scanners release 80% less radiation than the older machines used in the study; however, even low radiation doses can cause damage to genes and increase risks for developing cancer, said the AP. The study was just published online in the journal Lancet.
Meanwhile, NPR reports that the U.S. Food & Drug Administration (FDA) just issued a proposal to X-ray machine manufacturers for machines to be constructed with settings, and supplied with instructions, to minimize radiation to pediatric patients. The agency is also looking to including labeling on machines not recommended for use in children. Just one X-ray dose increases cancer risks, the NPR pointed out, noting that children are particularly sensitive to X-ray damage.
The FDA urges parents to discuss the medical necessity of suggested X-ray tests and alternatives, such as MRI or ultrasound. As we’ve written, CT scan and X-ray use is on a dramatic rise, with the tests used almost as a go-to diagnosis method over traditional bedside care. Often, a doctor will order one of these tests on a new patient based on an initial analysis when more traditional care could produce the same diagnosis. Several factors could be causing the sharp rise in X-rays, CT scans, fluoroscopy tests, and the like, including a doctor’s worries of potential malpractice charges for a missed diagnosis, patients (or their insurers) ability to pay for the scan, and pressure from healthcare facilities and device makers to use the tests as often as possible.
It’s likely the average child will receive at least 7 tests that emit radiation before they reach their 18th birthday, putting them at greater risk of suffering toxic radiation exposure, something that could impair brain and body development and increase future cancer risks. Unfortunately, there are no guidelines for treating children with these imaging tests.
The FDA believes that following its new guidelines will help reduce risks of radiation exposure. To help with developing its proposed rules and future regulation of the use of X-rays and CT scans on pediatric patients, the FDA has employed the aid of Alliance for Radiation Safety in Pediatric Imaging (ARSPI) and manufacturers, through the Medical Imaging and Technology Alliance (MITA). These groups are charged with developing the training and safety information for medical professionals specifically for using these tests in the future on children. The agency and these two groups have been working since February 2010 to develop these guidelines. The FDA has scheduled a public meeting next month to discuss the proposal, NPR said.