Genetic damage from radiation highlights need to protect physicians in cath lab

A pair of studies published in October added to the growing literature on the harmful effects of radiation exposure to interventional cardiologists in the cath lab.

One study showed brain-specific microRNA (miRNAs) was significantly downregulated in operators exposed to radiation when compared to age- and sex-matched controls who had no occupational exposure. Another found genetic biomarkers for DNA damage/repair rose significantly after procedures that required radiation but then returned to baseline levels after 24 hours. Notably, the use of protective leg shielding mitigated the damage.

Charles E. Chambers, MD, who authored an editorial accompanying the studies in Circulation, spoke to Cardiovascular Business about this research and recent developments that could improve operator safety. Here are three key takeaways from that conversation:

1. These studies were novel because they showed genetic damage related to radiation exposure.

This differs from previous research, Chambers said, which centered on hard clinical outcomes or the development of orthopedic injuries from years spent wearing heavy lead clothing to shield against radiation.

“But now these two studies suggest that radiation is what we were worried about all along. It really does increase genetic alterations,” he said.

Because dysregulated miRNA has been linked to certain forms of epilepsy, Alzheimer’s disease and brain cancers, the study authored by Andrea Borghini and colleagues raises the concern that radiation may also tie into cognitive impairment.

“We’re fortunate, I think, that there aren’t more tumors, there aren’t more long-term ramifications from radiations, but I also wonder—one of the articles mentioned dementia—are we missing subtleties, occupational hazards in people that are chronically exposed to radiation that we’re attributing to aging, but are enhanced by radiation?” Chambers said. “The importance of protecting the patients is always there, but we should not underestimate the importance of protecting the operator and staff.”

2. Advances have been made in dose-reduction software, but hospitals need to pay up.

In 2010, the FDA challenged the industry to limit unnecessary radiation, and manufactures responded by developing equipment that could capture acceptable images at lower doses of radiation. But now the onus is on hospitals to get the most up-to-date, safe equipment, Chambers said.

“The challenge anymore is with cost containment,” Chambers said. “If you can turn on an x-ray tube and get an image, is that enough? These studies that show subtle changes in genetics and DNA must make us realize that everything we can do to decrease radiation has to be in everyone’s best interest.”

3. Robotic procedures could eventually limit operators’ radiation risk.

Reducing dosage is one way to reduce risk. Two others are increasing the distance from the radiation source and decreasing the time spent near that source.

Robotic technology has the potential to address both concerns.

By having an operator perform most of a procedure away from a patient—possibly even in another room—the radiation hazard would be significantly reduced, Chambers pointed out. But even then, staff members working near the patient would require as much protection as possible.

Robotic percutaneous coronary intervention (PCI) could soon grow in popularity, as Corindus Vascular Robotics recently announced a partnership with the Mayo Clinic to test the feasibility of ‘telestenting,’ or remote PCI, with its CorPath GRX System.

“There’s some challenges involved and costs, but that, too, is the next generation,” Chambers said.

But for now, Chambers said physicians, medical physicists, hospital administrators, governing bodies and equipment manufacturers must work together to create the safest possible environment for everyone in the cath lab.

“At the end of the day it’s all about the patient. … The best way of reducing operator exposure is reducing patient exposure,” Chambers said.