A Clinical Trial of The Evaluation of Environmental Exposure in Yttrium 90 Radioembolization

Abstract

Aim: The aim of this study is to measure the dose rate of two different forms of Y-90 microsphere used for radioembolization and to evaluate the results according to radiation safety regularities. Material and Methods: 19 patients were enrolled in study (Age:61±1.5, F/M:12/7). As a result of the evaluation of the physicians, 7 patients were treated with TheraSphere and 12 patients were treated with SIR-Sphere. Dose rate measurements were taken at the stage of activity preparation, injection, radioactive wastes and discharge of patients via electronic dosimeter (ED). Results: The staff was exposed to dose rate of 1,3.10-4 μSv/MBq.h during activity preparation stage, 2,4.10-4 μSv/MBq.h in injection stage for Therapshere application. For SIR-spheres application, the staff was exposed to dose rate of 24,5.10-4 μSv/MBq.h during activity preparation stage, 10,1.10-4 μSv/MBq.h in injection stage. The average amount of dose received per operation was calculated 0.92±0.48 μSv in TheraSphere and 3.22±0.89 μSv in SIR-Spheres. For discharge of the patients, the average dose rate recorded from 1 m was found 4±0.28 μGy.h-1 for TheraSphere and 3.2±0.15 μGy.h-1 for SIR-Spheres. The dose rate of radioactive wastes measured from the surface of the container which contained the radioactive wastes generated after the application was 0.5±0.1 μSv.h-1 for TheraSphere and 1.1±0.08 μSv.h-1 for SIR-Spheres. Conclusion: It is emphasized that Y-90 Therasphere application provides radiation safety more than SIR-Spheres because of its closed system, even so both applications shows low dose rate around the patient and short-term storage of radioactive wastes after application would be sufficient.