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12 November 2010

Scan Ban

That’s a pretty disturbing statistic published in the Archives of Internal Medicine. It just adds to the controversy stirring around CT (computed tomography) scan use. A tipping point that led to more investigation of CT scan use was this: General Electric applying for approval of CT scans as tests for colon cancer. It’s a request made because, even though the practice of screening healthy patients with CT scans has become commonplace, many insurers are hesitant to pay for the scans.
The FDA moved to approve GE’s request—until agency scientists had objections. They said that the increased cancer risk from CT scans’ radiation would outweigh any potential benefits. Gastroenterologist and former FDA consultant Julian Nicholas—who trained at Oxford University and the Mayo Clinic—was one of those objecting. He wrote in an e-mail that approval would “expose a number of Americans to a risk of radiation that is unwarranted and may lead to instances of solid organ abdominal cancer.”
That didn’t set too well. Nicholas says, “I was first ignored, then pressured to change my scientific opinion, and when I refused to do that, I was intimidated and ultimately terminated.”

Nicholas wasn’t alone in questioning the safety of CT scans. FDA medical officer Dr. Robert Smith of Yale and Cornell Universities said, “The increased radiation exposure to the population could be substantial and would raise a serious public health/public policy issue.” Smith’s input was dismissed, too.
At present, approval for G.E.’s request is still pending.

 The scientists have cause for concern, though. The average American is exposed to seven times more non-therapeutic radiation than in 1980—due largely to the popularity of CT scans which expose patients to as much radiation as 400 chest x-rays. Additionally, the number of CT scans in the U.S. has increased from three million per year in 1980 to 70 million today. Scientists say that this extra radiation exposure kills 14,500 people a year and may be responsible for 29.000 new cases of cancer annually.

More people are paying extra attention to scan usage, too. California’s governor, Arnold Schwarzeneggar, has signed a bill that requires hospitals and clinics to record radiation doses for CT scans and to report any overdoses to patients and their doctors. Why? Hundreds of patients who underwent brain scans for stroke in 2008 and 2009 were overdosed. For example, in Cedars-Sinai Medical Center in Los Angeles alone, 269 patients received up to eight times the radiation expected—overdosing that continued for 18 months before the hospital discovered it. Five other California hospitals had higher than expected radiation doses given to patients.

Likewise, the New York Times reported that excessive radiation doses were given to more than 400 patients, including some at Huntsville Hospital in Alabama, who got up to 13 times the expected amount. Those who received the high doses of radiation reported a variety of symptoms, including hair loss, mental confusion, headaches and memory loss. Those folks also face a higher risk of brain damage and cancer.
Prior studies indicate that up to one-third of CT scans are unnecessary or can be replaced with less risky—and less expensive—tests. Experts believe that 20 million adults and more than one million children are receiving unnecessary CT scans each year.

CT scans aren’t the only sources of excessive radiation, though. For example, mammograms emit radiation, too, that exposes the heart and breast tissue to dangerous ionizing radiation that directly causes DNA damage, which can lead to increased cancer risk. Dr. John Gofman, an authority on the health effects of ionizing radiation, estimates that 75% percent of breast cancer could be prevented by avoiding or minimizing exposure to ionizing radiation—from mammography, x-rays and other medical or dental sources. Other means of mammography for those who choose to have it include thermography technologies (using no radiation) or even digital mammography (using a smaller dose of radiation).

When it comes to CT scans (and other radiation), here’s something to think about. The New England Journal of Medicine found that survivors of the 1945 atomic bombs faced significant increases in lifetime cancer risk, but they also found that the levels of radiation the atomic bomb survivors were exposed to by the bombings is equivalent to receiving only two or three CT scans.
No wonder there’s a growing scan ban.

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