Use of Fluoroscopy and Potential Long-Term Radiation Effects on Cataract Formation

The lens of the eye is extremely susceptible to radiation and long-term exposure can induce cataract formation. Our objective was to explore the risk of cataract formation for urologists at our institution.

A retrospective review of a multisurgeon database of fluoroscopic cases between October 2013 to December 2014 was queried. Procedures were performed by different subspecialties and ranged from stent insertion/ureteroscopy to percutaneous nephrolithotomy. Fluoroscopic parameters were recorded from all cases and the radiation dosimetry was calculated through methods described by the National Council on Radiation Protection. The data were extrapolated to determine the risk of cataract formation. The technical specifications of the GE OEC 990 mobile C-arm unit were used for calculations.

A total of 780 cases were analyzed, of which 182 were endourology cases. Average fluoroscopic time was 34.86 seconds per case. Average tube potential and current were 86.84 kV and 1.95 mA, respectively. Pediatric urologists utilized fluoroscopy the least, 11.84 seconds per case (p = 0.0022). Endourology trained faculty had fluoroscopy exposure of 68.35 seconds per case (p < 0.0001), whereas others were exposed 26.24 seconds per case (p < 0.0001). For the highest exposed urologist, the estimated dose to the eyes was 5.64 μGy per case. Total estimated cumulative dose over the study timeframe was 997.58 μGy, or 748.19 μGy per year.

The defined threshold in the absorbed dose for cataract formation is 0.5 Gy. Resident exposure was the highest, at 11% of the annual limit, and the most exposed urologists had an estimated dose of 5% of the annual limit. At current exposure levels, it would not be feasible to reach the stated safety limit during 50 to 60 years of practice. However, changing exposure guidelines could result in stricter safety limits.