Overuse of CT scans will lead to new cancer deaths, a study shows -- latimes.com

Overuse of CT scans will lead to new cancer deaths, a study shows -- latimes.com

Widespread overuse of CT scans and variations in radiation doses caused by different machines -- operated by technicians following an array of procedures -- are subjecting patients to high radiation doses that will ultimately lead to tens of thousands of new cancer cases and deaths, researchers reported today.

Several recent studies have suggested that patients have been unnecessarily exposed to radiation from CTs or have received excessive amounts, but two new studies published Tuesday in the Archives of Internal Medicine are the first to quantify the extent of exposure and the related risks.

Each year that current scanners are used, researchers reported, 14,500 deaths could result.

In one study, researchers from UC San Francisco found that the same imaging procedure performed at different institutions -- or even on different machines at the same hospital -- can yield a 13-fold difference in radiation dose, potentially exposing some patients to inordinately high risk.

While a normal CT scan of the chest is the equivalent of about 100 chest X-rays, the team found that some scanners were giving the equivalent of 440 conventional X-rays. The absolute risk may be small for any single patient, but the sheer number of CT scans -- more than 70 million per year, 23 times the number in 1980 -- will produce a sharp increase in cancers and deaths, experts said.

"The articles in this issue make clear that there is far more radiation from medical CT scans than has been recognized previously," Dr. Rita F. Redberg of UC San Francisco, editor of the journal, wrote in an editorial accompanying the reports. Even many otherwise healthy patients are being subjected to the radiation, she said, because emergency rooms are often sending patients to the CT scanner before they see a doctor. ...