NCPA - National Center for Policy Analysis


November 29, 2007

Overuse of diagnostic CT scans may cause as many as 3 million excess cancers in the United States over the next two to three decades, according to the authors of a reported in the New England Journal of Medicine (NEJM).

Other findings:

  • Today, about 62 million CT scans are performed nationwide every year, up from 3 million in 1980.
  • As many as 5 million scans are now done in children, who are 10 times more sensitive to radiation than adults.
  • As a result, medical exposure to radiation, mainly through CT scans, has replaced environmental radon as the dominant source of radiation exposure for the U.S. population.

The study's authors insist they're not trying to discourage all use of CT scans; as it is an invaluable tool in many cases.  The problem is that doctors too often overlook its risks.   "About one-third of all CT scans that are done right now are medically unnecessary," says David Brenner of Columbia University, lead author of the NEJM study.

More alarmingly, Brenner and his co-author, Eric Hall, also of Columbia, say many doctors don't realize that just a scan or two can bathe a patient in roughly the same amount of radiation as the atomic bomb delivered to the Japanese survivors of Hiroshima and Nagasaki standing a mile or two from ground zero.  And many people receive multiple scans over a lifetime.

Source: Steve Sternberg, "Study: Unnecessary CT scans exposing patients to excessive radiation," USA Today, November 29, 2007.

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