Report says children exposed to too much radiation by CT scans

Dec 11 2006

According to a report by a Canadian expert, children are being exposed to excessive amounts of radiation when they have a CT scan.

Ontario's auditor general Jim McCarter has said in a report that in almost 50 per cent of the cases he studied, hospitals did not reduce the exposure setting when children took the high-tech diagnostic exam.

McCarter says because children's organs are more sensitive to radiation than those of adults, a child who has a CT scan on their abdomen using an adult setting is exposed to eight times the radiation an adult would be exposed to in the same setting.

The findings are part of the auditor general's annual report.

McCarter says research has shown that increased exposure to radiation, over time, can cause radiation-induced cancers.

His report criticises Ontario hospitals for not analyzing the number of CT scans adults and children are receiving or monitoring the doses of radiation received by each patient.

He says he has come across 58 children who received more than one CT scan a year, 14 who had more than three scans a year and one child had 6.

According to McCarter up to 20 per cent of cases, in adults and children are getting CT unnecessarily.

He also says some medical staff were not aware that CT scans expose patients to significantly more radiation than a common X-ray and while both British and American hospitals have guidelines about how much radiation a patient should receive, Ontario does not.

He has also found cases of radiologists who were not wearing dosimeters, a protective device that measures their own level of radiation exposure.

However experts have condemned the report and say diagnostic testing for children is not risky and the public need not be concerned.

Michael Bronskill, a medical biophysics professor at the University of Toronto, says the report contains little new information and though there is always a risk of radiation exposure when someone undergoes an X-ray or CT scan, the diagnostic benefits far outweigh such risks.

According to Bronskill everyone is exposed to small amounts of radiation on a daily basis, and the long-term cancer risk posed by diagnostic machines is low.

However Bronskill says hospitals could benefit from employing medical physicists who are trained in the art of balancing radiation dosage with image quality.

At present radiologists interpret the images the radiation technologists produce.

He said provincial legislation currently does not allow medical physicists to serve as a hospital's radiation safety officer.