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CT scan radiation warnings ignored by FDA

March 30, 2010 12:00:00 AM PDT
Approximately 70 million CT scans are performed in the U.S. every year. But now, government scientists say the FDA has ignored warnings about the radiation risk.Radiologists say a 10-minute virtual colonoscopy can detect colon polyps 90 percent of the time. But are they worth the risk of exposure to radiation?

"For example, the radiation dose of a single CT scan of the abdomen is roughly equivalent to the dose of 400 chest X-rays," says Dr. Jeffrey Shuren, FDA.

An FDA panel is asking the government to make an official recommendation on the use of CT scanning.

One doctor claimed he was rebuffed when he told higher-ups he was worried over radiation dosing from diagnostic scanning tests -- especially virtual colonoscopies.

Researchers estimate as many as 14,000 people may die every year from radiation-induced cancers. Gastroentorologists who perform traditional colonoscopies endorse that method as the best screen for cancer. While radiologists like Dr. Ira Smalberg, with St. John's Health Center, say CT scans when used appropriately are the way to go.

"The benefits of finding a clinically important polyp that could then removed and prevent a colon cancer far outweigh the radiation risk," said Dr. Smalberg.

Since there's been a lot of focus about the radiation risk and CT scanners, doctors admit that the volume of this type of testing has gone down. But until more Americans are screened for colon cancer, Dr. Smalberg says this technology is an opportunity to save lives.

"If 95 or a 100 percent of adults were actually getting screened when they were eligible then maybe they'd have a point," said Dr. Smalberg. "But I think there is a great need for screening of our elderly population at high risk for colon cancer."

With the best minds in medicine passionately disagreeing, what should a patient do?

Experts say if you have a CT scan planned right now don't cancel it. Talk to your doctor. Find out why you're having it done, and see if the benefits really outweigh the risks.

One more point in the debate: if you have a virtual colonoscopy, and a polyp is found, you still have to have a traditional colonoscopy to remove it. So some experts feel you might as well just have one procedure.

But radiologists counter many people are scared of the procedure and if it weren't for the virtual version, they might not have one at all.