Shielding efficiency of novel tungsten rubber against radionuclides of Tc-99m, I-131, F-18 and Ga-68
Kijima, K; Krisanachinda, A; Pasawang, P; Hanaoka, K; Monzen, H; Nishimura, Y; ,
Background/Aim: A newly introduced tungsten-containing rubber is a potentially useful shielding material against radiation from radionuclides because it is lead-free, containing as much as 90% fine tungsten powder by weight. This study aimed to investigate the shielding efficiency and usefulness of tungsten-containing rubber against radiation from radionuclides. Materials and Methods: Shielding efficiency due to different thickness of tungsten-containing rubber was measured for the following radionuclides mostly used in nuclear medicine such as Tc-99m, I-131, F-18 and Ga-68 then the linear attenuation coefficient (mu) and half value layer (HVL) were calculated. The assessment of energy spectrum with and without tungsten-containing rubber of half value layer were evaluated for Tc-99m, I-131, F-18 and Ga-68 . Results: The mu of Tc-99m, I-131, F-18 and Ga-68 were 1.357 mm(-1), 0.096 mm(-1), 0.076 mm(-1), and 0.063 mm(-1), respectively. The HVL for Tc-99m, I-131, F-18 and Ga-68 were 0.51 mm, 7.22 mm, 9.12 mm, and 11.00 mm, respectively. By energy spectrum analysis, decrease in the detection counts were confirmed regardless of the radionuclides and the energy peaks. Conclusion: Tungsten-containing rubber has adequate radiation shielding efficiency for radionuclides. The protection with tungsten-containing rubber of radionuclides in consideration of HVL, the half-life, energy and activity are safe and efficient, and could, therefore, be employed as shield in clinical site.