Y-90 microsphere 로부터 생성되는 제동복사선의 차폐를 위한 차폐체 개발 연구

Development of shielding device for bremsstrahlung radiation from Y-90 microspheres

Purpose Yttrium-90 (Y-90) is high-energy beta emitters (Eβ, max = 2.28 MeV) with the mean penetration depth of 2.5 mm in tissue. Radioactive microspheres containing Y-90 is widely used for the transarterial radioembolization of hepatocellular carcinoma. However, bremsstrahlung radiation from Y-90 can cause the external radiation exposure to medical staff who handle the Y-90 microspheres. In this study, shielding device for Y-90 microspheres was developed to minimize the external radiation exposure. Materials and Methods Y-90 microsphere shielding device was made from 6 mm thicknesses of tungsten including the lead glass window. Radiation shielding ability of Y-90 microsphere shielding device was evaluated using 4 GBq of SIR-Spheres® Y-90 microspheres. The bremsstrahlung radiation was measured using radiation survey meter. Results The mean radiation dose of Y-90 microspheres in acrylic shield was 261.7 ± 2.3 μSv/h (n=5) at 10 cm away from the shield. With the additional tungsten shielding device, it was 23.7 ± 1.3 μSv/h (n=5). Thus, the bremsstrahlung radiation dose was decreased by 90.9%. At 50 cm away from the shield, bremsstrahlung radiation was reduced by 89.2% after using tungsten shielding device. Conclusion During the preparation and radioembolization of Y-90 microsphere, medical staff are exposed to external radiation. In this study, we demonstrated that the use of tungsten shielding device devices significantly reduced the amount of bremsstrahlung radiation. Y-90 microsphere tungsten shielding device can be highly effective in reducing the bremsstrahlung radiation.