Effectiveness of Radiation Protection Caps for Lowering dose to the Brain and the Eye Lenses.

PURPOSE: This work was designed to study the effectiveness of radiation protection caps in lowering the dose to the brain and the eye lens during fluoroscopically guided interventions. MATERIALS AND METHODS: Two types of radiation protection caps were examined with regards to their capacity to lower the radiation dose. One cap is equipped with lateral flaps, the other one is not. These caps were fitted to the head of an anthropomorphic Alderson-Rando (A.-R.) phantom. The phantom was positioned aside an angiographic table simulating the position of the first operator during a peripheral arterial intervention. One of the brain slices and both eyes of the A.-R. phantom were equipped with thermoluminescence dosimeters (TLDs). RESULTS: The analysis of the data showed that the cap without lateral flaps reduced the dose to the brain by 11,5-27,5 percent depending on the position within the brain. The cap with lateral protection flaps achieved a shielding effect between 44,7 and 78,9 percent. When evaluating the dose to the eye, we did see an increase of dose reduction from 63,3 to 66,5 percent in the left eye and from 45,8 to 46,8 percent in the right eye for the cap without lateral protection. When wearing the cap with lateral protection we observed an increase of dose reduction from 63,4 to 67,2 percent in the left eye and from 45,8 to 50,0 percent in the right eye. CONCLUSION: Radiation protection caps can be an effective tool to reduce the dose to the brain and the eyes.

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 µGym2. The more experienced urologists yielded a mean DAP of 166 µGym2 for stage I and 415 µGym2 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 µGym2). 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.