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A variety of concerns have arisen over CT or CAT scans. A new study shows that some types of CT scans may elevate the risk of cancer over the long-term. Also, the Food and Drug Administration is broadening an investigation into several hundred cases of radiation overdoses; those occurred with a special type of CT scan used to image the brain.
NPR's Patti Neighmond explains.
PATTI NEIGHMOND: The FDA is looking into more than 300 cases of radiation overdose at three hospitals in Los Angeles County and one hospital in Huntsville, Alabama. FDA officials say there may well be a lot more cases at hospitals nationwide. These are special types of CT scans which look at blood vessels. They're typically done on the brain to diagnose a stroke or aneurysm, but they require more radiation than typical CT scans.
Dr. Jeffrey Shuren is acting director of the FDA division that oversees radiological devices.
Dr. JEFFREY SHUREN (Acting Director, Center for Devices and Radiological Health): You can think about a regular CT scan to the brain as being about the equivalent in radiation of 100 chest X-rays. And a CT profusion scan of the brain is several hundred chest X-Rays. And the patients in these cases received - who got excess radiation - received the equivalent of several thousand chest X-rays.
NEIGHMOND: The FDA sent alerts to hospitals and health care facilities nationwide that performed these specialized CT scans, asking them to double check the machines to make sure they're configured correctly.
Shuren says it's not clear how such overdoses could have happened.
Dr. SHUREN: It could be due to human error. It could be due to problems in the design of the CT scanners, or it could be a combination of both.
NEIGHMOND: The companies that make the scanners involved, GE Healthcare and Toshiba, say they're cooperating with the FDA and hope to resolve the situation quickly. The hospitals say the same thing. For the patients, though, the experience has been life-changing. The amount of radiation they received, three to eight times the recommended dose, can lead to radiation poisoning.
In Los Angeles, 64-year-old Trevor Rees had two of these perfusion scans after suffering what was later diagnosed as a stroke.
Mr. TREVOR REES: I had hair falling out, obviously washing my hair. I had flaky skin. My face was red. You know, people kept saying to me, oh, you know, you look really well. You look suntanned. You know, well, I haven't been anywhere, you know? I've just been in hospital.
NEIGHMOND: And about 10 days after he came home from the hospital, Rees says the nausea set in.
Mr. REES: Nausea is nonstop. You know, it's just 24 hours a day.
NEIGHMOND: Rees lost 20 pounds fairly quickly and he wasn't overweight. Today, he's quite thin and walks with a cane. He's easily fatigued and often quite dizzy. He's suing the hospital where he had the scan.
His lawyer, Bill Newkirk, says he has several clients with the same story.
Mr. BILL NEWKIRK (Attorney): That amount of radiation produces tissue distraction. We found that consistently, among all of the people who have contacted my office - and there's a large number of them - all have characteristic symptomology that is consistent.
NEIGHMOND: Similar to the problems suffered by Trevor Rees.
So far, reports of radiation overdose have only been reported with these special scans that look at blood vessels. But some health experts say all scans add up to too much, increasing the overall risk of cancer.
In a study from the Archives of Internal Medicine released yesterday, Dr. Rebecca Smith-Bindman from University of California, San Francisco found major variations in the amount of radiation used for all types of CT scans and estimated cancer risk from the scans.
Dr. REBECCA SMITH-BINDMAN (Professor of Radiology, University of California, San Francisco): For an abdominal and pelvis CT scan, I think if a 40-year-old woman underwent a CT scan, her risk of getting cancer from that CT scan was about one in 250. So one in 250 patients who underwent that kind of CT scan would get cancer directly from that examination.
NEIGHMOND: And that was the average. But for the patients who got higher doses or more frequent scans, cancer risk increased even more.
Smith-Bindman says standards for radiation dose should be universal and tightly regulated. And she says CT scans can be just as effective with lower doses of radiation than what's used today.
Patti Neighmond, NPR News.
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