Risk of Radiation-Induced Cataracts: Investigation of Radiation Exposure to the Eye Lens During Endourologic Procedures.

BACKGROUND

Due to new radiobiologic data, the International Commission on Radiological Protection recommends a dose limit of 20 mSv per year to the eye lens. Therefore, the IAEA International Basic Safety Standard and the European council directive 2013/59/EURATOM require a reduction of the annual dose limit from 150 to 20 mSv. Urologists are exposed to an elevated radiation exposure in the head region during fluoroscopic interventions, due to the commonly used overtable X-ray tubes and the rarely used radiation protection for the head. Aim of the study was to analyze real radiation exposure to the eye lens of the urologist during various interventions, during which the patient is in the lithotomy position.

MATERIALS AND METHODS

The partial body doses (forehead and apron collar) of the urologists and surgical staff were measured over a period of 2 months. 95 interventions were performed on Uroskop Omnia Max workplaces (Siemens Healthineers, Erlangen, Germany). Interventions were class-divided in less (stage I) and more complex (stage II) interventions. Two dosimeter-types were applied, well-calibrated electronic personal dosimeter Mk2 and self-calibrated thermoluminescent dosimeter-100H (both Thermo Fisher Scientific, Waltham, MA). The radiation exposure parameters were documented using the dose area product (DAP) and the fluoroscopy time.

RESULTS

The correlation between DAP and the apron dose of the urologist was in average 0.07 μSv per 1 μGym. The more experienced urologists yielded a mean DAP of 166 μGym for stage I and 415 μGym for stage II procedures. The interventionist was exposed with 10 μSv in mean outside the lead apron collar. The mean dose value of the eye lenses per intervention was ascertained to 20 μSv (mean DAP: 233 μGym).

CONCLUSIONS

The study setup allows a differentiated and time-resolved measurement of the radiation exposure, which was found heterogeneous depending on intervention and surgeon. In this setting, ∼1000 interventions can be performed until the annual eye lens dose limit is achieved.