CT Scans: A Radioactive Risk

Article excerpt

MY DENTIST AND I have been bickering for decades. Steve advocates diagnostic X-rays; I argue that ionizing radiation, an established cancer risk, is not worth the benefit of catching a cavity early. Every couple of years, he threatens to dump me as a patient and I agree to a few X-rays after factoring in the benefits of his skill and his generous hand with the nitrous oxide.

Our negotiations rest on conjoined principles of Western medicine: risk-benefit analysis and informed consent.

But when it comes to the far greater risk of a "procedure performed more than 150,000 times a day in the United States...most consent forms are silent," notes Georgetown University's Adrian Fugh-Berman, in a report for the Hastings Center, an independent bioethics research institute.

Computed tomography (CT) scans take multiple X-ray images from different angles and link them into cross-sections of body tissues and organs. Researchers at Yale found that only a minority of U.S. academic medical centers inform patients about alternatives to diagnostic CT-including sonograms and MRIs-or about the radiation.

One abdominal CT, says the Food and Drug Administration (FDA), exposes a patient to 500 times more radiation than a conventional chest X-ray. Exposure from a single full-body CT scan is within the same range as doses that increased the cancer risk of Japan's A-bomb survivors. Full-body scans can cause a one in 1,250 increased chance of dying from cancer, Radiology reports. That risk more than doubles for the 2-3 million children scanned, and leaps again for the third of those kids given at least three scans, according to the National Academy of Sciences.

Of course, many CT scans are well worth the risk. They can be superb diagnostic tools that result in more effective treatments and, possibly, cures.

But early diagnosis does not always mean longer survival. "If I pick up a tumor that is one centimeter today and you live five years, or I pick it up four years later and you live one year, it's the same thing," Dr. Elliott Fishman, a professor of radiology and oncology at Johns Hopkins Hospital, told the New York Times.

The risk-benefit equation skews further at facilities touting CT scan screening for apparently healthy people.

"Are you at risk?" ask the big red letters of a Web pop-up ad. "Find out for only $99" for a heart scan at Pulse Medical Imaging, "located in the White Plains [NY] business district."

Or "Come to Florida, for a scan and a tan," flashes a Web ad for Healthiest Scan Center, where a pelvic, abdomen and chest scan will set you back $895, with a heart scan thrown in. …