Real-Time Monitor Cuts Radiation Exposure to Operators During Cardiac Cath

“Radiation is one of those things that people talk about but never really pay much attention to,” said Emmanouil S. Brilakis, MD, PhD, of the Dallas VA Medical Center (Dallas, TX), in a telephone interview with TCTMD. “Increasingly it's coming into the front line. [This study] shows there are things we can do… to minimize exposure for patients and operators.”

For the RadiCure study, Dr. Brilakis and colleagues tested the effect of the Bleeper Sv device (Vertec Scientific; Silchester, England)—which clips onto the operator’s lead apron and beeps at increasing frequencies with higher radiation exposure—plus usual safety measures among 18 operators (16 fellows and 2 attendings), all of whom received similar training on equipment use and radiation.

The trial included 505 patients (mean age 65 years; 99% men) undergoing coronary angiography (64%), PCI (11%), or both (25%) in 2 cath labs between January 2012 and May 2014. Patients were randomized to use (n = 253) or no use (n = 252) of the Bleeper Sv device. Radiation exposure to patient and operators (first and second) was measured in both groups with a separate silent dosimeter.

Patient characteristics were similar between the study groups, but those assigned to the Bleeper Sv device were older, less likely to be men, and had a higher frequency of PAD. Radial access was used in 18%, and chronic total occlusion (CTO) PCI made up 7% of the procedures.

Substantial Protection for Operators

The device was associated with 36% and 29% relative reductions in radiation exposure for first and second operators, respectively, compared with the control group (P < .001 for both). The differences were upheld for diagnostic angiography (P < .001 for both operators) but did not reach statistical significance for PCI.

Further, these results were consistent among subgroups, including patients with CTO PCI, prior CABG, radial access, above median air kerma radiation exposure, and above median BMI, and for cases performed with different fluoroscopy equipment. The effect of the Bleeper Sv was consistent throughout the entire study period and did not vary among operators.

Use of the device did not affect patient exposure, as measured by air kerma or dose area product. Fluoroscopy time (6.0 vs 6.6 minutes; P = .223) and contrast utilization (122 vs 125 mL; P = .184) were numerically lower during procedures in which the Bleeper Sv device was used.

Distraction vs Safety

The issue with radiation, according to Dr. Brilakis, is that operators cannot sense it in the cath lab. The advantage of an auditory-feedback device is that operators can make real-time changes to shield or x-ray positioning, he said. “Behavior changes by using this.”

In a telephone interview with TCTMD, Stephen Balter, PhD, of Columbia University Medical Center (New York, NY), said he has informally used similar devices in training fellows for many years. “It's a very effective tool that has the advantage that it works to the ears so it doesn't distract the eyes from what they're doing,” he said.

Dr. Brilakis noted that in rare cases—in the occasional obese patient or when the radiation dose needs to be high for another reason—“[the device] can become annoying because the beeping sound is very intense.” For these cases, he added, it would be beneficial if the device had a silencing button.

Because of this potential for distraction, Dr. Balter doesn’t advocate for this type of device to be used by every operator on a daily basis. “If you're stuck with 3 or 4 people wearing these beeping devices, that’s not a good idea [due to the noise],” he said. “As a training device, it's wonderful.”

Best to Establish Good Habits Early

Once operators learn where to optimally stand and position devices and shields, then they can wean themselves off of this type of device, Dr. Balter said. “What this study does is show that this experience works…. I think it should be used until they are confident that they are optimally managing their personal radiation exposure.”

Dr. Brilakis agreed. “It's all based on experience,” he said. “A common thing I see is people don't really pay attention to this at all. They go in, the patient isn't positioned properly, the x-ray machine is positioned poorly, and they do the x-ray much longer than they need to. It just doesn't register to them that this is something that can give you radiation and it's a bad thing.

“If someone is extremely good at it and very conscious at all times, then he will do great,” he continued. “But the reality is that even the ones who are very good at this very often get distracted, so having a reminder is a good thing.”

Dr. Brilakis encouraged the use of the Bleeper Sv device, or something similar, for all fellows. “This is the best time to establish good radiation practices,” he said. “If you learn this correctly when you are a fellow, you are going to be much better off than if you don't.”

Disclosures:

• RadiCure was supported by the Dallas VA Research Corporation and the Department of Veterans Affairs.
• Dr. Brilakis reports receiving honoraria/speaker fees from Abbott Vascular, Asahi, Boston Scientific, Elsevier, Somahlution, St. Jude Medical, and Terumo and research grants from Guerbet and that his spouse is an employee of Medtronic. 
  
• Dr. Balter reports no relevant conflicts of interest.

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