Fully Suspended Radiation Protection Effective in Small Study

A weightless apron suspended from above the operator is capable of providing better protection against radiation to the head and upper body than standard lead garments, new research shows.

Writing in Catheterization and Cardiovascular Interventions, investigators led by Federica Zanca, PhD (Palindromo Consulting, Leuven, Belgium), say this approach also has advantages over individual aprons, glasses, and shields in that it provides a single barrier that does not required the operator to limit their movement to maintain optimal protection from whatever they are wearing.

The study followed three operators who performed a total of 277 angiography or PCI procedures at a single institution over about 2 years. During the first phase of the study, the operators wore standard lead radiation protection garments, including apron, thyroid lead collar, low leaded flaps, an upper mobile leaded glass screen suspended from the ceiling, and leaded glasses. In the second phase they used the suspended Zero-Gravity system (Biotronik), which provided shielding from the top of their head to their calves.

Compared with procedures performed with standard lead, operators during the Zero-Gravity phase had average median reductions in radiation dose of 78.9% to the left eye and 95.6% to the left upper arm during angiography, while decreases were 83% to the left eye and 93% to the left upper arm during PCI.

According to Zanca and colleagues, a suspended full-body shield has the potential to create a “nearly zero-radiation work environment.”

Ryan Madder, MD (Spectrum Health, Grand Rapids, MI), who has used the Biotronik Zero-Gravity system in his lab for nearly 10 years, welcomed the data, noting that radiation protection in the cath lab is a double-edged sword.

“The risk of orthopedic injuries, particularly spinal injuries over time, is the downside of wearing protective garments,” he told TCTMD. “The thing I think is very attractive about this Zero-Gravity system is that not only is it associated with reducing a physician's radiation dose in a pretty substantial amount, but it also allows the operator to not have to support the weight of lead garments on their own body.”

Young Cardiologists Need to Pay Attention

The new data confirm those of a prior study by Madder’s group, which showed that real-time radiation exposure to the chest and head of operators during PCI was significantly reduced with the suspended-lead system compared with traditional lead apparel.

“Our study however adds to it through organ dose measurements of brain and eyes in an anthropomorphic phantom,” Zanca and colleagues write. In addition to the study’s clinical aspect, they developed the ex vivo “phantom” model that consisted of a mannequin, simulating an operator, that had thermoluminescent detectors inserted into the head and eyes, as well as dosimeters place on the temple and thyroid. Radiation measurements were then performed with the mannequin wearing a standard lead apron or the Zero-Gravity system.

Too often we see in cath labs around the country that people only become interested in radiation safety when a staff member or a physician develops a cancer. Ryan Madder

Compared with the apron, the average dose reduction in the ex vivo model was 83% to the operator’s brain, 92% to the left eye, 86% to the right eye, 97% to the left temple, 92% to the thyroid, and 100% to the torso.

As Zanca and colleagues note, disproportionate reports of left-sided brain tumors have been documented in interventional cardiologists and electrophysiologists, raising concern that an operator’s head is being exposed to radiation doses that could be as much as 10 to 20 times higher than body parts protected by lead aprons. They further contend that radiation safety needs to be constructed into the design of cath labs, rather than relying on operators and staff to protect themselves.

“I think young cardiologists—whether they're interventional cardiologists, or electrophysiologists, or even interventional echocardiographers—all of those individuals need to be paying attention to studies like this,” Madder observed. “Too often we see in cath labs around the country that people only become interested in radiation safety when a staff member or a physician develops a cancer. It's a shame that that's often what it takes to change attitudes towards radiation safety, and it shouldn't be that way. We should be paying attention to this from the outset of our careers to really try to prevent these things from happening.”