For decades, providers have used lead aprons to shield patients from radiation exposure during X-rays, but recent research has found that lead shielding may be unnecessary, and medical groups are beginning to recommend against the practice, Mary Chris Jaklevic reports for Kaiser Health News.

Toolkit: Access our imaging leader's dashboard

An unnecessary practice?

Since the 1950s, health care providers have been advised to cover testicles and ovaries during an X-ray. That recommendation came from a study in fruit flies that suggested radiation exposure might harm DNA and lead to birth defects.

However, in the last decade, radiology professionals have reassessed the value of shielding patients during X-rays, and their findings suggest it's time to change the practice, Jaklevic reports.

The amount of radiation a patient is exposed to during an X-ray is roughly one-twentieth of what it was in the 1950s, Jaklevic reports, and data shows that the radiation patients are exposed to for diagnostic imaging causes no measurable harm to ovaries and testicles.

Donald Frush, a radiologist at Lucile Packard Children's Hospital Stanford and chair of Image Gently Alliance, said, "What we know now is that there is likely no [hereditary] risk at all."

And according to Rebecca Marsh, a medical physicist at the University of Colorado Anschutz Medical Campus, there's also no evidence that fetuses are harmed by X-ray radiation, even by a fairly high amount that can come from a CT scan.

In fact, instead of benefitting patients, lead shields may lead to problems, Jaklevic reports. According to the American Association of Physicists in Medicine (AAPM), lead shields can be difficult to accurately place and frequently don't actually shield the area they're intended to be shielding. And when the shields are placed correctly, they can accidentally cover up areas of the body that are supposed to be part of the X-ray, which means the process would need to be repeated, AAPM says.

In addition, lead shields can prompt the automatic controls on an X-ray machine to expose the person to more radiation in order to provide an image of what's on the other side of the shield, Jaklevic reports.

Moreover, lead shielding doesn't address "scatter," which happens when radiation "ricochets" throughout the body and leaves energy in tissues, Jaklevic writes. According to Jaklevic, scatter is radiation's biggest effect.

Groups recommend against lead shields

With all this in mind, many medical groups recently have recommended against lead shielding. Last April, the AAPM recommended lead shielding be "discontinued as routine practice," a recommendation that was supported by the American College of Radiology and the Image Gently Alliance, among other groups, Jaklevic reports.

Similarly last spring, FDA proposed removing lead shielding from federal recommendations and is expected to issue a final rule in September. The National Council on Radiation Protection and Measurements is also likely to issue a statement recommending against lead shielding, Jaklevic reports.

A difficult transition

While the recommendation for lead shielding is changing, getting providers to stop the practice could be difficult, Marsh said.

"There's this big psychological component, not only with patients but with staff," she said. "How do you approach something that is so deeply ingrained in the minds of the health care community and the minds of patients?"

Kate Feinstein, chief of pediatric radiology at the University of Chicago Medicine, said the recommendation to stop lead shielding "came as kind of a shock" and felt at odds with what radiologists are taught. She said her department already takes steps to ensure a shield doesn't interfere with an exam. "We apply our shields correctly, and our technologists are incredibly well-trained," she said.

Still, Feinstein said her department is considering ending the practice.

For their part, the AAPM said that hospitals should create lead shielding policies that consider the fact that the practice may "calm and comfort" patients. "I don't think any of us are advocating to never use it," Frush said.

Some hospitals will also have to deal with state regulations regarding lead shielding, Jaklevic reports. At least 46 states, as of spring 2019, required shielding of reproductive organs if they're near the area being X-rayed unless the shielding would impair the exam's diagnostic quality, according to the AAPM.

If the practice does change, there will be a need for outreach to dentists, who also use lead shielding during X-rays, according to Mahadevappa Mahesh, chief physicist at Johns Hopkins Hospital. "It's high time we bring them into the discussion."

The American Dental Association has said the lead shielding "may not be necessary" but is continuing to recommend the practice to shield the thyroid "whenever possible."

Marsh said that there will also be a need to support technologists when they are educating patients and families on the practice of lead shielding "so they are not feeling like they are walking into a disastrous conversation" (Jaklevic, Kaiser Health News, 1/15).