TCT.14: Radiation management, from no tech to high tech

WASHINGTON, D.C.—It may not take much more effort than an invitation to a colleague to improve a cath lab’s radiation safety, a medical physicist said at the Transcatheter Cardiovascular Therapeutics conference in a session on existing and developing approaches.  

“We need to educate the physicists about cath lab procedures,” said Stephen Balter, PhD, of the radiology department at Columbia University Medical Center in New York City, one of four panelists to speak Sept. 15 about imaging integration and radiation reduction. “Very few of my colleagues in medical physics or radiation safety ever have seen a procedure.”  

Human factors may be the downfall in safety programs. Badges worn by interventialists to measure radiation exposure provide data on exposure levels, but they are passive and Balmer described compliance as poor. Dashboards can track and flag measures such as fluoroscopy rates but they require a person to monitor them and understand the displayed data.

“The limitation right now is that the technology uses workers, primarily cardiologists, to control what is going on,” including nonclinical functions involving imaging equipment, he said. “I would like to see automation take over these things because once computers are working right they are much more diligent than people for doing repetitive tasks.”

Safety training can make clinicians aware of the hazards and safeguards but they may not be cognizant of habits that increase the risk of exposure. Balter used an anecdote as an outside observer watching a cardiologist with his foot on the x-ray pedal during a procedure who should have been—but was not— alerted by staff.

He encouraged interventional cardiologists to seek out their medical physicist colleagues and invite them into the cath lab to observe a procedure and discuss the reasoning for techniques and their importance.

“If you treat them like medical students, they will learn and very often they will see things that you can’t,” he proposed. “But they can’t do this if they are not allowed in the lab with patients. They have to see clinical procedures.”

Charles Chambers, MD, of Hershey Medical Center in Hershey, Penn., reiterated the importance of training, education and safety mandates for making vendors and operators sensitive to the issue. That has led to dose management and other tools for ensuring adequate image quality with reduced dose.

James Goldstein, MD, director of research and education at Beaumont Health in Royal Oak, Mich., pointed out that safety protocols such as wearing lead aprons may lead to back, knee and other orthopedic problems over time. “We are kind of like the NFL [National Football League]; we are all getting banged up,” Goldstein said. “We are working like football players from the ‘40s with the leather helmets and no face masks.”

Radiation shielding offers one approach for added protection for the operator and staff. He described a system he developed that combines fixed upper and lower shields, interconnecting radiation drapes, interlocking patient drapes and sterile drapes. A first-in-man report published in 2013 showed that use of the system (Trinity Radiation Protection System, ECLS) during cardiac catheterizations resulted in exposure levels barely above zero.

Lindsay S. Machan, MD, of Vancouver Hospital and Health Sciences Center in Canada, and Giore Weisz, MD, of Shaare Zedek Medical Center in Jerusalem, concluded with innovative technologies that further protect cardiologists and staff in the cath lab. Machan shared details on an imaging approach using novel hardware and software to focus on the region of interest during a procedure while Weisz reviewed a robotic system that allows the operator to perform procedures while seated behind a protective screen.

The robotic system (CorPath 200, Corindus Vascular Robotics) mitigates occupational hazards such as radiation exposure, the burden of lead aprons and potential injuries, he said. A 2014 study comparing robotic PCI and conventional PCI reported high technical and clinical success. The robotic system reduced radiation exposure by 95 percent, he said.

 “I, as an operator, think that what is reasonable is zero,” Weisz said, referring to the term as low as reasonably achievable. “This should be our optimal dose, zero radiation.”

Goldstein and Machan report having equity interests in the companies making the devices they discussed.