From Our 2008 Archives

ER Radiation May Raise Cancer Risk

Multiple X-rays and Other Tests May Put Emergency Room Regulars at Risk

By Jennifer Warner
WebMD Health News

Reviewed By Louise Chang, MD

May 29, 2008 — Emergency room visitors may be exposed to potentially dangerous levels of radiation from X-rays, CT scans, and other tests that may increase their risk of cancer in years to come.

Researchers say emergency room physicians do not routinely keep track of the cumulative amount of radiation their patients receive. In fact, until now, they had no way of knowing how much radiation a patient has been exposed to during one or multiple visits.

A new study shows emergency room patients received an average radiation dose of 45 millisieverts. But 12% of patients received 100 or more millisieverts of radiation during the five-year study period — a dose that exceeds the recommended safety limits and may increase the risk of cancer.

"Our research hopefully will affect the habits of physicians who routinely order medical imaging diagnostic studies in their practices," researcher Timothy Bullard, MD, MBA, of the Orlando Regional Medical Center, says in a news release. "We also hope that our research will further promote the need for electronic medical records with portability and encourage the development of an individual patient cumulative exposure estimate tool."

ER Radiation Unchecked

In the study, presented this week at the annual meeting of the Society for Academic Emergency Medicine in Washington, D.C., researchers measured the amount of radiation that a random sample of patients at two urban emergency rooms received over the course of five years.

Overall, an average of 10.8 tests involving radiation exposure, such as X-ray, CT scans, and nuclear imaging tests (tests that use small amounts of radioactive material to produce pictures of internal parts of the body not visible on X-rays), were performed on each patient studied.

Nearly two-thirds of these tests were X-rays (63%), 26% were CT scans, 5% were nuclear studies, and 2% were mammography.

Researchers found more than 70% of ER-related radiation exposure came from three primary types of diagnostic imaging tests: CT scans of the abdomen and pelvis, nuclear imaging of the heart, and CT scans of the chest.

They say if these findings apply to the average emergency room visitor nationwide, a substantial number of people may be at increased risk of developing cancer during their lifetime because of excessive radiation exposure from diagnostic ER testing.

They estimate that an additional six cancers above the national average would be attributable to radiation exposure in this population.

SOURCES: Annual meeting of the Society for Academic Emergency Medicine, Washington, D.C., May 29, 2008. News release, Wiley-Blackwell.

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