Study: Popular whole-body CT scans for ER use have dangers

Hospitals may need to rethink their policies on whole-body computed tomography (CT) imaging for the evaluating severely injured patients in the ER, according to a new study of radiation dangers associated with the procedure.

Whole-body scans have been accepted practice in many trauma centers for a decade, as a way to identify internal injuries or other difficult-to-diagnose conditions, according to a report at Medscape Medical News. However, CT scans can expose patients to levels of radiation of 20 Millisievert (mSv) or more, which is twice the amount that will give a 40-year-old adult a 1-in-1,000 chance of future cancer, according to National Academy of Science data, Medscape points out.

Researchers admitted they were troubled by the paradox of balancing radiation risks, which might not harm the patient for years, against the risk of immediate harm from an injury that goes unidentified through other diagnostic methods.

"There is little published information about the diagnostic accuracy of the pan-scan or its impact on decision-making in the setting of severe trauma," they say. "There is, however, evidence that established tests, such as ultrasound and plain X-rays, have too low a sensitivity to reliably exclude injuries of the abdomen, chest, spine and pelvis when negative ... This leads to a bizarre situation: what is the ultimate reference standard to determine the accuracy of an accepted diagnostic gold standard, such as CT?"

The ultimate findings were grim: Pan-scanning may be as much as 26 times more likely to harm patients in the long run than to assist physicians with injury detection in the ER, according to Dirk Stengel, director of the Center for Clinical Research at the Unfallkrankenhaus Trauma Center, Berlin, Germany.

The study's authors blame media hype and public demand for much of the increase in pan-scans for trauma patients, despite there being no long-term studies of the radiation dangers. "The number of trauma centers in developed countries that have adopted the pan-scan algorithm may now exceed Gladwell's tipping point, and it will be impossible to turn back this trend," the authors say.

The effects of the study in the U.S. may be more dramatic, given that the Centers for Medicare & Medicaid Services just released its own standard, OP-15, which it wants hospitals to use to gauge when an ER patient should (or shouldn't) receive CT scans. The standard is largely intended to prevent unneeded scans, and reduce patients' long-term radiation risks. Critics say the standard is flawed, but CMS plans to publish data supporting OP-15 on Hospital Compare, soon.

The study's authors say that despite risks, there may be a place for pan-scanning in the ER, but its use must be carefully--and scientifically--applied only to patients for whom its benefits outweigh its costs. And finding that sweet spot may take a number of clinical trials and exploration, they note.

To learn more:
- read the Emergency Medicine Australasia study
- check out Medscape Medical Newscoverage