MP63-03 DOES THE SURGEON'S HEIGHT AND DISTANCE FROM THE C-ARM AFFECT BRAIN AND EYE RADIATION EXPOSURE DURING FLUOROSCOPY?

Abstract

INTRODUCTION AND OBJECTIVES: Fluoroscopy can expose operating room (OR) staff to scattered ionizing radiation, even if they are not directly in the radiation path and high volume surgeons have an increased risk of brain tumors. The inverse square law declares that direct radiation exposure is reduced exponentially as one gets further away from the source. However, scattered radiation is much more difficult to quantify. The purpose of this study was to evaluate the impact of physician height and distance from the scatter source upon radiation exposure to the brain and eyes of the operating surgeon during simulated percutaneous nephrolithotomy (PCNL). METHODS: PCNL was simulated using cadaver models for the patient and surgeon. Radiation exposure to the surgeon's brain and eyes was measured using 8 different dosimeters, which were placed on each eye and in the bilateral frontal, parietal, and temporal lobes. Fluoroscopy was performed with fixed settings of 90 kVp and 3.8 mA for 10 minutes per trial with the surgeon facing forward. Radiation scatter to the surgeon's head was measured at two different heights: 5′2″ and 5′10″. For each height, 5 trials were completed with the simulated surgeon directly adjacent or 6 inches away from the OR table for 10 total trials. RESULTS: The mean total radiation dose at all 8 sites was 17.7 mrem for the 5'2” height compared to 5.7 mrem for the 5'10” height (p<0.001) at 6 inches from the table. For surgeons of both heights, measured scattered radiation was higher when standing 6 inches from the table compared to directly adjacent to the table. For the 5'2” height, doses were higher in the left eye (43.4 vs. 14.8 mrem; p<0.001), left frontal lobe (14.0 vs. 8.8 mrem; p=0.022), right frontal lobe (15.4 vs. 6.6 mrem; p<0.001), and left temporal lobe (9.8 vs. 5.4 mrem; p = 0.005) and were higher at the right eye, right temporal lobe, and bilateral parietal lobes but did not reach significance. Radiation dose was higher in the front four dosimeters compared to the back four dosimeters (14.3 vs. 5.3 mrem; p<0.001). CONCLUSIONS: Shorter surgeons receive higher scattered radiation exposure to the brain and eyes during fluoroscopy. Contrary to the inverse square law, physicians that work farther away from the table during fluoroscopic procedures may be at greater risk for radiation exposure to the brain and eyes. This may be due to shielding within the image intensifier at closer proximities. Further studies are necessary to confirm this novel finding and to further characterize scatter radiation in general.