CT scans during childhood may be linked to later risk of leukemia, brain tumors

The Los Angeles Times reports in the “Science Now” blog that CT scans during childhood may increase the risk of later developing brain tumors and leukemia, according to a study published online in The Lancet. The good news is that the risk is very, very low.

Investigators “studied nearly 180,000 children who underwent at least one CT scan between 1985 and 2002 in the radiology departments of 70% of the United Kingdom’s hospitals. They estimated the dose of radiation absorbed in each scan, then linked the data to cancer incidence and mortality reports in the UK National Health Service Registry and calculated excess incidence of brain tumors and leukemia.”

The AP reports, “They found 74 of them were diagnosed with leukemia, while 135 had brain tumors.” The researchers “concluded the risk of brain tumors was tripled if children had two to three scans and the risk of leukemia was tripled with five to 10 scans.” The study received funding from the US National Cancer Institute.

The New York Times “Well” blog reports, “the American College of Radiology issued a statement urging parents not to refuse needed CT scans, especially for potentially life-threatening conditions like head and spine injuries, pneumonia complications and chest infections.”

However, “the organization also lists conditions for which CT should not be the first choice; one is suspected appendicitis in children, for which the group recommends that ultrasound be used first, followed by CT only if the ultrasound is equivocal.”

The Wall Street Journal reports that according to Marta Schulman, chair of the American College of Radiology Pediatric Imaging Commission, the research adds to the notion that patients should undergo imaging procedures only when essential, and with the smallest radiation dose possible.

The CNN “The Chart” blog quotes Dr. Schulman as saying, “If an imaging scan is warranted, the immediate benefits outweigh what is still a very small long-term risk.” According to Dr. Schulman, “Parents should certainly discuss risk with their provider, but not refuse care that may save and extend their child’s life.”

Bloomberg News reports, “The Image Gently Campaign and the Alliance for Radiation Safety in Pediatric Imaging, based in Cincinnati and funded by the Society for Pediatric Radiology and other founding organizations, is pushing for lower radiation doses in children.”

The NPR “Shots” blog reports that “Andrew Einstein of Columbia University Medical Center, who wrote an analysis of the study that’s being published along with the paper in the journal The Lancet,” said, “It’s the first paper that’s convincingly established that radiation exposure at low doses – in this case from CT scans – is associated with an increased cancer risk to patients.”

HealthDay reports, “Lead study author Amy Berrington de Gonzalez, from the US National Cancer Institute, said” that “all the previous studies about the potential risk of CT scans have been theoretical studies using models from other radiation-exposed populations.”

WebMD reports, “While the study directly links CT imaging with cancer risk later in life, the overall risk to the individual child remains very low.”

Enter your email to subscribe to Dr. Walt's blogs.

You have successfully subscribed to the newsletter

There was an error while trying to send your request. Please try again.

Dr. Walt Larimore will use the information you provide on this form to be in touch with you and to provide updates and marketing.