New guidelines to cut needless radiation exposure

By Sheilah Downey

The dangers of overdosing on CT scans has been widely reported, with some people exposed to more radiation than nuclear power plant employees, according to a recent New England Journal of Medicine report.

New guidelines released today may reduce unnecessary CT scans on children after head trauma accidents, says a UC Davis study.

Nearly one-half million children each year visit the emergency room for traumatic brain injury (TBI), say numbers from the Centers for Disease Control.

"A substantial percentage of children who get CT scans after apparently minor head trauma do not need them," says the UC Davis release, "and as a result are put at increased risk of cancer due to radiation exposure."

After analyzing 42,000 children with head trauma at 25 hospitals, researchers found that nearly one-quarter of children under the age of two were given unneeded scans. One in five children older than two were also given unnecessary CT scans.

"When you have a sample size this large, it is easier to get your hands on the truth," said Dr. Nathan Kuppermann, lead author of the study and professor of pediatrics at UC Davis Children's Hospital.

Kuppermann said study results show that "CT use can be safely reduced by eliminating its application in those children who are at very low risk of serious brain injuries."

Kuppermann and colleagues developed a set of "prediction rules" for the study, a method of factoring in the circumstances of each trauma. Predictions were determined on a varying set of conditions, including symptoms, age of victim, circumstances of the injury and other factors.

Researchers stressed that the rules should not replace individual clinical judgment.

"We're arming the clinician with the best available evidence so that they can make the best decisions," said Dr. James Holmes, co-author of the report and professor of emergency medicine at UC Davis. "There certainly are instances when the risks of radiation are worth it, such as in cases of blunt head trauma which results in changes in neurological status of clinical evidence of skull fractures."

For years studies have shown that radiation exposure increases the risk of various types of cancer.

If the new guidelines are applied appropriately, said researchers, the unnecessary use of CT scans could be greatly reduced.

Results of the study were published online today and appear in an upcoming edition of the Lancet.