Safety, Quality and Management group, Indira Gandhi Centre for Atomic Research, India.
Safety, Quality and Management group, Indira Gandhi Centre for Atomic Research, India.
Appl Radiat Isot. 2022 Feb;180:110020. doi: 10.1016/j.apradiso.2021.110020. Epub 2021 Nov 17.
In-vivo whole body monitors are calibrated with various types of phantoms like Bottle Mannikin absorption phantom (BOMAB), IGOR phantom, Masonite cut sheet phantom, realistic numerical phantoms (NORMAN, ICRP voxel phantom). These phantoms contain either point sources, rod sources, uniform source or radionuclides distributed in soft tissues etc. In this study the efficiency values of Shadow Shield wholebody counter (SSC) for Cs and Co obtained theoretically using ICRP adult voxel male reference phantom (ICRP-AM) having sources distributed in soft tissues and muscles ICRP-AM(S) are compared with the measured efficiencies of Indian BOMAB phantom having mid axial source distribution (BOM-I(A)). The results show that the efficiency value of BOM-I(A) for Cs and Co is 30% and 20% lower respectively compared to that of ICRP-AM(S). This is due to the variation in size, composition and source distribution between the two phantoms. Study using Indian Voxel phantom shows that the increase in the size of ICRP-AM contributed to an increase of 14% for Cs. In case of Co the size did not have any influence. Uniform distribution has 9% and 17% higher efficiency than axial distribution for Cs and Co respectively as shown by the simulation study using uniformly filled Indian BOMAB phantom (BOM-I(U)). The actual tissue composition and source distribution in soft tissue as shown by Indian voxel has efficiencies 12-14% higher compared to BOM-I(U). The systemic error due to the axial source distribution is recognized and quantified to be 22-25% lower compared to that of a realistic phantom with radionuclides in soft tissue and muscle. This study has resulted in an efficiency of the system using Indian realistic Voxel phantom. The efficiencies are 0.65 CPS/kBq for Cs and 0.49 CPS/kBq for Co.
体内全身监测仪使用各种类型的体模进行校准，例如瓶式曼尼金吸收体模 (BOMAB)、IGOR 体模、美松切片体模、逼真数值体模 (NORMAN、ICRP 体素体模)。这些体模中包含点源、棒源、均匀源或放射性核素分布在软组织等中。在这项研究中，使用分布在软组织和肌肉中的 ICRP 成人体素男性参考体模 (ICRP-AM) 理论上获得的 Shadow Shield 全身计数器 (SSC) 对 Cs 和 Co 的效率值与具有中轴源分布的印度 BOMAB 体模 (BOM-I(A)) 的测量效率进行了比较。结果表明，与 ICRP-AM(S) 相比，BOM-I(A) 对 Cs 和 Co 的效率值分别低 30%和 20%。这是由于两个体模之间的大小、组成和源分布存在差异。使用印度体素的研究表明，ICRP-AM 的尺寸增加导致 Cs 增加了 14%。对于 Co，尺寸没有任何影响。模拟研究表明，与轴向分布相比，Cs 和 Co 的均匀分布效率分别高出 9%和 17%，这是使用均匀填充的印度 BOMAB 体模 (BOM-I(U)) 进行的。实际的软组织组成和源分布如印度体素所示，其效率比 BOM-I(U)高 12-14%。由于轴向源分布而导致的系统误差被识别并量化为比具有放射性核素分布在软组织和肌肉中的真实体模低 22-25%。这项研究得出了使用印度逼真体素的系统效率。对于 Cs，效率为 0.65 CPS/kBq，对于 Co，效率为 0.49 CPS/kBq。
