The U.S. Food and Drug Administration should step in to protect patients from radiation from CT scanners, according to one expert in the ongoing debate over the safe use of medical imaging.

Others say doctors should stop ordering so many scans, which often find conditions that might have been better left untreated. But they argue against FDA regulation, which may keep companies from investing in new innovations.

Both sides of the debate, published on Wednesday on the New England Journal of Medicine website, reflect ongoing concerns about how to best use advanced diagnostic tests.

Overuse of the costly scans has been a concern of policymakers for the past few years, prompting cuts in Medicare reimbursement. And recent studies on radiation risks from computed tomography or CT scans and several cases of accidental radiation overdoses have drawn the attention of the FDA.

A CT scan of the chest exposes a patient to more than 100 times the radiation of an X-ray and an abdominal CT scan is roughly equivalent to 400 chest X-rays.

A report last year by the National Council on Radiation Protection and Measurement found that Americans receive seven times more radiation from diagnostic scans than in 1980.

“We need to start taking this seriously,” said Dr. Rebecca Smith-Bindman of the University of California San Francisco, and a visiting research scientist at the National Cancer Institute, one of the National Institutes of Health.

“Radiation doses are higher than they should be and they vary dramatically within and between facilities and that is not acceptable,” said Smith-Bindman, who wrote one of the commentaries calling for the FDA to regulate CT scans.

Part of the problem is that there are no uniform standards for how much radiation is needed to produce a scan, which means two patients may be getting vastly different amounts of radiation to get the same diagnosis.

Smith-Bindman advocates for regulation similar to what already exists now at the FDA for mammograms.

Part of the problem, she said, is agreeing on a standard dose, especially when obese patients need more radiation to produce the same image.

“What we’ve done as a community is to say, ‘It’s hard. We can’t do it,’” she said in a telephone interview.

ANTI-IMAGING PERFECT STORM

But heaping more regulation on an industry that has already been squeezed by Medicare cuts may squelch the kind of innovation that produced CT scanners in the first place, says Dr. Bruce Hillman, a professor of radiology at the University of Virginia in a commentary.

“There already is a strong regulatory bias against imaging,” said Hillman, who argues that doctors need to show more restraint in ordering imaging tests.

“If this becomes much worse, things will become so draconian there will no longer be an investment in innovation,” Hillman said in a telephone interview.

“There is this perfect anti-imaging perfect storm going on right now”.

Hillman said the real threat from using advanced imaging technology is when doctors stumble on a potential problem and need to follow up.

He said doctors need to be more critical about using medical imaging, reserving it for patients who really need it.

“We need to convince physicians that a quest for certainty is impossible, costly and is harmful because of indirect diagnoses,” he said.

SOURCE: The New England Journal of Medicine, online June 23, 2010.