Protected and Unprotected Radiation Exposure to the Eye Lens during Endovascular Procedures in Hybrid Operating Rooms.

OBJECTIVE Radiation cataract has been observed at lower doses than previously thought. Therefore, the annual limit for equivalent dose to the eye lens has been reduced from 150 to 20mSv. This study evaluates radiation exposure to the eye lens of operators working in a hybrid operating room before and after implementation of a dose reduction program. METHODS From April-October 2019, radiation exposure to the first operator was measured during all consecutive endovascular procedures performed in the hybrid operating room using BeOSL Hp(3) eye lens dosimeters placed both outside and behind the lead glasses (0.75mm lead equivalent). Measured values were compared to data from a historic control group from the same hospital before implementation of a dose reduction program. RESULTS A total of 181 consecutive patients underwent an endovascular procedure in the hybrid operating room. The median unprotected eye lens dose (outside lead glasses) of the main operator was 0.049mSv for EVAR (n=30), 0.042mSv for TEVAR (n=23), 0.175mSv for complex aortic endovascular procedures (F/BEVAR; n=15) and 0.042mSv for peripheral interventions (n=80). Compared to the control period, EVAR had 75% lower, TEVAR 79% lower and F/BEVAR 55% lower radiation exposure to the unprotected eye lens of the first operator. The lead glasses led to a median reduction of the exposure to the eye lens by the factor 3.4. CONCLUSION The implementation of a dose reduction program has led to a relevant reduction of radiation exposure to head and eye lens of the first operator in endovascular procedures. With optimum radiation protection measures including a ceiling-mounted shield and lead glasses, more than 440 EVARs, 280 TEVARs or 128 FEVARs could be performed per year until the dose limit for the eye lens of 20 mSv would be reached.