A new study published online in The Lancet, a British medical journal, has found that CT scans in children can cause “small but significant” increases in the risk of brain cancer and leukemia, reports the New York Times.
The retrospective study was based on the records of nearly 180,000 children in Britain who had CT (computed tomography) scans between 1985 and 2002. One hundred and thirty-five cases of brain cancer and 74 cases of leukemia were eventually reported in that group, which the study authors tied to the radiation doses received during the scans. The more scans and the higher the dose of radiation, the higher a child’s risk of brain cancer or leukemia. That being said, childhood cancers are very rare, so although children under 15 who received two or three scans of the head had three times the risk of brain cancer as the general population, the risk remains very small.
Researchers said that CT scans should only be performed when necessary (for example, for diagnosing potentially life-threatening conditions, like pneumonia complications, chest infections and severe head or spinal injuries), and with the lowest possible dose of radiation. Researchers estimate that of the approximately four million children a year who receive CT scans in the U.S., about one-third of those are either unnecessary or could be replaced by ultrasound or MRI (magnetic resonance imaging), neither of which use radiation.
The American College of Radiology issued a statement in response to the study, urging parents to get CT scans when needed, and that the “immediate benefits [of a CT scan] outweigh what is still a very small long-term risk.” The ACR also recommended that parents keep a record of their child’s x-ray history and ask the following questions of their physician before their child receives a scan:
• How will having this exam improve my child’s health care?
• Are there alternatives that do not use radiation which are equally as good?
• Will my child receive a “kid-size” radiation dose?
• Is this facility ACR-accredited?
Has your child ever received a CT scan or other form of radiation? Were you nervous about the level of radiation?