AUSTIN — Lead glasses were modest at best for protecting against fluoroscopic radiation to the eye area, according to research presented here.
Across 125 fluoroscopically-guided procedures at one center, average radiation going to the right eye was 0.027 mGy and to the left eye 0.050 mGy, even with the lead glasses. Left unprotected, the right and left cheeks each got 0.032 mGy and 0.061 mGy of radiation.
The side of the face closer to the source therefore received about 1.89-fold higher doses, and lead glasses only offered a 9.5% to 14.2% incremental reduction in radiation, Edison Lee, DO, of the University of British Columbia Hospital and Vancouver General Hospital told the audience at the Society of Interventional Radiology’s annual meeting.
“The orientation of the head to the radiation source is critical, because this may significantly reduce impact of leaded glasses. We must be aware that scattered radiation comes from all directions,” Lee said. “Lead glasses may be providing a false sense of security to the interventionist.”
However, putting the monitor on the opposite side of the operator (across the table or above the patient, typical for distal radial or femoral access) rather than on the same side was associated with about half the radiation, according to the researcher.
Radiation was measured by Optically Stimulated Luminescent chips — glued onto the cheeks and under the lower eyelids of each operator — which were read immediately after each procedure using a Landauer MicroSTAR radiation dose chip reader. Cataracts are a known result of radiation to the eyes.
Lee’s group had performed procedures with fluoroscopy time ranging from 4 seconds to almost 1.5 hours; air kerma 2 to 6,335 mGy; and dose area product 16.9 to 148,333 µGym2. A ceiling-mounted shield was not used at all in 23 of those 125 cases, of which X-rays and liver mapping were some of the more common procedures.
The study should “emphasize that eyes get radiation and the eyes should be protected at all times as best [operators] can with all available techniques from glasses, shielding, and recognizing proper monitor position,” commented Charles Chambers, MD, of Penn State Heart and Vascular Institute in Hershey, who was not involved in the study.
The findings shouldn’t lead operators to think they should not wear glasses or hospitals to not pay for lead glasses for them, Chambers continued. “Do all you can to protect yourself. I agree with not allowing the ‘false sense of security’ so that all be done always, including wearing glasses!”
Nevertheless, “the poor performance of leaded glasses is not surprising and is in agreement with a prior simulation study,” commented Emmanouil Brilakis, MD, PhD, of the Minneapolis Heart Institute.
“Attention to the basics remains key: low frame fluoroscopy (6 or 7.5 fps), optimal positioning of the X-ray tube and receptor, minimizing use of cineangiography by using fluoro-store, standing as far as possible from the patient, etc.,” he told MedPage Today. “New technologies, like the ControlRad, Egg Medical, Ikomed, use of newer X-ray systems, robotic PCI [percutaneous coronary intervention], and real time radiation monitoring systems could further reduce radiation-related risks.”
Lee disclosed no conflicts of interest.