Researchers Urge Routine Use of Breast Shields During Chest CT Scans

Dec. 1, 2010 (Chicago) -- Breast shields should be used to spare the breast tissue from radiation in men and women undergoing CT scans of the lung.

So say researchers who found that the shield -- a thin piece of heavy metal placed in front of the chest - does not affect the diagnostic accuracy of the images.

Research has shown that breast shields reduce the dose of radiation to the chest by about 30%, says Terry Healey, MD, director of thoracic radiation at Alpert Medical School of Brown University in Providence, R.I.

That's important because "radiation can cause secondary cancers, especially in the breast tissue," he tells WebMD.

But many doctors are reluctant to use the shields because they can cause artifacts -- streaks or lines, for example -- on the images. "They worry that the images will be harder to read and this will compromise their diagnostic accuracy," Healey says.

That, however, has never been proven.

Breast Shields Do Not Affect Diagnosis

So Healey and colleagues studied 50 people who had chest CT scans before and after the routine use of breast shields at their institution. Most were having the scans to look for cancer or to examine lung nodules.

The shield was placed directly on the chest or elevated about 1/2 inch to 1 1/2 inches away from the chest.

In two-thirds of patients, the images had streaks or other artifacts. But none impacted the diagnosis, Healey says.

"We never missed a finding," he says.

Elevating the shield about an inch to an inch-and-a-half off the chest will reduce the chance of having an artifact, Healey says.

The study was presented here at the annual meeting of the Radiological Society of North America.

Asked to comment on the findings, Judy Yee, MD, vice chair of radiology at the University of California, San Francisco, tells WebMD that "there's no good reason not to use breast shields. The cost is relatively low and the benefit large."

They're particularly beneficial for younger patients (who are more susceptible to the effects of radiation) and women (as they're more likely to develop breast cancer), she says.

The cost of a breast shield is about $100, Healey says. "While they’re marketed for one-time use, we reuse them," he says.