USA
Congress urged to give FDA power to regulate CT scans
Amid growing concern over the safety of CT scans, some experts say Congress should give the Food and Drug Administration power to ensure that patients aren't exposed to dangerously high levels of radiation.
In an editorial in today's New England Journal of Medicine, radiologist Rebecca Smith-Bindman describes the fate of a 59-year-old schoolteacher, one of hundreds of patients across the USA who have received accidental overdoses from tests called brain-perfusion scans, which can help detect strokes.
The woman had a relatively harmless form of facial paralysis, called Bell's palsy, that went away on its own in a few weeks. But after her CT scan, the woman became sick and confused and lost her hair. Doctors later realized she had received 10 times the normal dose of radiation, the editorial says. Although the patient's radiation dose was displayed on the CT scanner console, a technologist didn't realize anything was wrong, the editorial says.
Patients today often get CT scans — and radiation doses — they don't really need even when they are performed correctly, says Smith-Bindman of the University of California-San Francisco. In the schoolteacher's case, doctors could have ordered a routine head CT that exposes patients to one-tenth as much radiation as normally provided by brain-perfusion scans, she says.
Doctors have become so entranced by the clarity of images from CT scans, however, that they don't think about the extra radiation risk, Smith-Bindman says. Yet a patient who gets a single CT scan — which uses multiple X-rays — has up to a 1 in 80 chance of developing a cancer caused by the test. That's especially alarming, she says, given that 1 in 10 Americans today have a CT scan each year.
The American College of Radiology provides guidance to doctors about when to use CT scans, says John Patti, chair of the group's board of chancellors. But many doctors aren't following those voluntary standards, says the University of Virginia's Bruce Hillman, who wrote an accompanying editorial in the medical journal.
Congress could set clearer standards by giving the FDA authority to regulate how CT scans are used, Smith-Bindman says. A 1992 law regulating mammograms, for example, has reduced radiation exposure and helped women everywhere get the same high-quality care, she says.
Although asking the FDA to regulate CT scans would help, it wouldn't be simple, says David Brenner of Columbia University Medical Center. Mammograms are used for one purpose, he notes, but CT scans have dozens of uses, such as detecting cancer and examining the heart.
(Published by USA Today - June 24, 2010)