Shifting away from shield use
Some groups rethinking practice of lead aprons on patients during X-rays
Patients have come to expect a technician to drape their torsos with a heavy lead apron when they get anX-ray, but new thinking among radiologists and medical physicists is upending the decadesold practice of shielding patients fromradiation.
Some hospitals are ditching the ritual of covering reproductive organs and fetuses during imaging exams after prominent medical and scientific groups have said it’s a feelgood measure that can impair the quality of diagnostic tests and sometimes inadvertently increase a patient’s radiation exposure.
The about-face is intended to improve care, but it will require amajor effort to reassure regulators, health careworkers and the public that it’s better not to shield.
Themovement also has yet to gain much traction among dentists, whose offices perform more than half of allX-rays.
“There’s this big psychological component, not only with patients but with staff,” said RebeccaMarsh, amedical physicist at the University of Colorado AnschutzMedical Campus in Aurora, Colorado. “How do you approach something that is so deeply ingrained in the minds of the health care community and the minds of patients?”
Covering testicles and ovaries duringX-rays has been recommended since the 1950s, when studies in fruit flies prompted concern that radiation might cause birth defects. Only in the past decade did radiology professionals start to reassess the practice, based on changes in imaging technology and a better understanding of radiation’s effects.
Lead shields are difficult to position accurately, so they often miss the area they are supposed to protect. Even when in the right place, they can obscure areas a doctor needs to see, resulting in a need to repeat the process, according to the American Association of Physicists inMedicine.
Shields can also cause automatic exposure controls on anX-raymachine to increase radiation to all parts of the body being examined in an effort to “see through” the lead.
Moreover, shielding doesn’t protect against the greatest radiation effect: “scatter,” which occurs when radiation ricochets inside the body, including under the shield, and eventually deposits its energy in tissues.
Still, Dr. Cynthia Rigsby, a radiologist at Chicago’s Ann& RobertH. Lurie Children’sHospital, called themove away from shielding a “pretty substantial” change. “I don’t think it’s going to happen overnight,” she added.
In April, the physicists’ association recommended that shielding of patients be “discontinued as routine practice.” Its statementwas endorsed by several groups, including the American College of Radiology and the Image Gently Alliance, which promotes safe pediatric imaging.
Around the same time, the Food and Drug Administration proposed removing fromthe federal code a 1970s recommendation to use shielding. A final rule is expected in September.
In 2020, theNational Council on Radiation Protection andMeasurements, which gives guidance to regulatory bodies, is expected to release a statement supporting a halt to patient shielding. However, experts continue to recommend that health care workers in the imaging area protect themselves with leaded barriers as a matter of occupational safety.
Groups in Canada and Australia have endorsed the change, and amovement to abandon lead shields is underway in Great Britain, according toMarsh.
Marsh, who’s helping direct the educational effort, said perhaps a dozen U.S. hospitals have changed their official policies, but “most hospitals are starting to have the conversation.”
Chicago’s Lurie Children’sHospital is launching an “Abandon the Shield” campaign to educate staff, patients and caregivers before it stops shielding this spring, Rigsby said. Shielding is used for most of the 70,000X-ray procedures performed annually at Lurie.
A few miles away, at the University of ChicagoMedicine hospitals, the recommendation to stop shielding “came as kind of a shock,” said Dr. Kate Feinstein, chief of pediatric radiology.
Feinstein said it seems contrary to what radiology professionals are taught, and she’s uncertain howit applies to her department, which already takes steps to reduce the chance that a shield will interfere with an exam.“We apply our shields correctly, and our technologists are incredibly well trained,” she said.
Nevertheless, Feinstein said, her department is weighing a halt to routine shielding.
As of last spring, at least 46 states required shielding of reproductive organs if they are close to the area being examined, unless shieldingwould interfere with the diagnostic quality of the exam, according to the medical physicists’ association.
The amount of radiation needed for anX-ray is about one-twentieth of what itwas in the 1950s, and scientists have found no measurable harm to ovaries and testicles of patients from radiation exposure that comes from diagnostic imaging after decades of looking at data.
“Whatwe knownowis that there is likely no (hereditary) risk at all,” said Dr. Donald Frush, a radiologist at Lucile Packard Children’sHospital Stanford in Palo Alto, California.