Research published this week in the Journal of the American Medical Association Pediatrics projected 4870 cancers would be caused by the four million CT scans carried out on children each year. Researchers suggested reducing the dose of the highest-level scans could dramatically reduce the number of cases.
Children are more vulnerable to the ionising radiation of CT scans, which produce 100 times or more the radiation of a chest X-ray.
At monthly health board meetings, Dr Sijnja has warned of the dangers of CT scan radiation for patients of all ages.
Contacted yesterday, he said he believed New Zealand took a more cautious approach in the use of CT scans for children.
''I think [New Zealand is] probably not using the saturation approach that [the United States] do there. We're a little bit more discerning with the examinations that we do.
"But I think we've got to be very watchful and very careful that we don't overuse ... particularly the CT scanning, for that reason.''
Although children were more at risk, it was potentially problematic for adults, particularly if they had multiple scans, Dr Sijnja said.
New Zealand did not keep a patient register of CT scans, which increased the risk of patients having too many. While he did not want to overstate the risks, he believed awareness of the issue should be higher.
''[Clinicians] should be thinking very hard: 'Do we really need this scan? Will it make a difference to what we're going to do?','' he said.
Dr Sijnja said that as a GP, he was not authorised to refer patients for CT scans.
University of Otago associate professor of cancer epidemiology Brian Cox said the American insurance model, and a perceived risk of litigation, meant more scans were carried out in the United States than in New Zealand.
He did not think the risk should be overstated.
''Sometimes, there are risks with procedures, but it has to be balanced against the immediate problem that's in front of you. There are risks of not doing the procedures, as well.''
