If you have a full body computed tomography screening (CT scan) once a year for 30 years your chances of getting cancer go up from 1 in 1200 to 1 in 50, say researchers in a new study.





Study stirs debate over full-body scans' cancer risk
By Liz Szabo, USA TODAY
People who have full-body CT screenings to detect potential health problems are exposed to about as much radiation as some survivors of the Hiroshima and Nagasaki atomic bombings, a study in Tuesday's journal Radiology reports.
Proponents of the increasingly popular full-body scans say the exams are safe and can discover disease in early, more curable stages. The risk of cancer, they say, is too small to worry about.

In Tuesday's article, however, researchers say the scans expose people to about 13 milligrays of radiation, which is about the same exposure suffered by people who were 1½ miles from the center of the World War II atomic blasts in Japan, says David Brenner, the study's lead author and professor of radiation oncology and public health at Columbia University Medical Center. (Related story: Q&A: Scanning the risks)

Brenner says the cancer risk varies with age. Among 45-year-olds, for example, a single full-body scan will cause fatal cancer in one in every 1,250 people who have the exams. One full-body scan increases a person's lifetime cancer risk by a fraction of 1% — a small amount, considering that about one in five Americans overall die from cancer.

But opponents of the scans say even a small increase in mortality is significant because full-body screenings have never been scientifically proven to benefit healthy patients.

Richard Morin, chairman of the American College of Radiology's commission on medical physics, notes that the radiation from traditional CT scans of specific organs, which are used to diagnose disease in people with specific symptoms, is worth the risk if patients stand to benefit from treatment.

Michael Brant-Zawadzki, medical director of radiology of Hoag Memorial Hospital Presbyterian in California, describes the link between cancer and body scans as "remote and not proven." Some full-body CT technology provides one-third less radiation than those levels that Brenner cited in his article, Brant-Zawadzki says.

Doctors don't know how many full-body screenings of healthy people are performed, although they believe they make up a growing portion of the up to 65 million CT scans done every year.

Jasson Gilmore of ScanDirectory.com, an online referral service aimed at healthy people seeking full-body screenings, estimates that business has increased 25% in the past year.

http://www.usatoday.com/news/health/2004-08-30-scans-risk_x.htm