Children who undergo multiple CT scans face a slightly higher risk of developing leukemia or brain cancer, according to research published online Wednesday in The Lancet. The authors, however, stressed that the risk remains small.
Researchers looked at records of 180,000 people who underwent a CT scan before age 22 in Britain between 1985 and 2002. Of them, 74 were diagnosed with leukemia and 135 with brain cancer between by 2008. The authors estimated that risk grew with the more scans and the more radiation the child received.
Two or three scans of the head in children under 15 tripled the risk of brain cancer compared with the general population, and five to 10 scans tripled the risk of leukemia, The New York Times reports. But the risk still remained extremely low: 4.5 cases of leukemia per 100,000 people under 20, and 3.5 cases of cancer of the brain or central nervous system.
Yet there are times when CT scans are the best option. "Although clinical benefits should outweigh the small absolute risks, radiation doses from CT scans ought to be kept as low as possible and alternative procedures, which do not involve ionizing radiation, should be considered if appropriate," The authors wrote.
Meanwhile, the American College of Radiology urged parents not to refuse needed CT scans.
"CT scans are most often performed on children who have experienced trauma to the head, neck or spine, or may suffer from neurological disorders or injury, or may need fast and accurate evaluation for complex and life threatening clinical issues such as pneumonia complications or chest infections," Marta Schulman, chair of the Pediatric Imaging Commission, said in a statement.
"If an imaging scan is warranted, the immediate benefits outweigh what is still a very small long-term risk. Parents should certainly discuss risk with their provider, but not refuse care that may save and extend their child's life."
But the group maintains that CT should not be the scan of choice in all cases, such as appendicitis, for which it recommends ultrasound be used first.
"Use of CT scans continues to rise, generally with good clinical reasons, so we must redouble our efforts to justify and optimize every CT scan," said Andrew Einstein, a cardiac radiologist at the Columbia University Medical Centre in New York, in an AFP article.
The use of CT scans is growing, though at a lesser rate than a decade ago, and they remain prevalent in ERs, as FierceHealthIT recently reported.
The radiology industry, meanwhile, has been working to reduce children's exposure to radiation from medical tests. The Food and Drug Administration recently called for equipment that can scale down to the smallest patients, for example. And collaborators from six U.S. children's hospitals also are building the first pediatric CT dose index registry based on patient size.