Pérez-Calatayud J, Granero D, Casal E, Ballester F, Puchades V
Department of Atomic, Molecular and Nuclear Physics and IFIC, University of Valencia-CSIC, Burjassot, Spain.
Med Phys. 2005 Jan;32(1):28-36. doi: 10.1118/1.1834835.
In this study, complete dosimetric datasets for the CSM2 and CSM3 Cs-137 sources were obtained using the Monte Carlo GEANT4 code. The application of this calculation method was experimentally validated with thermoluminescent dosimetry (TLD). Functions and parameters following the TG43 formalism are presented: the dose rate constant, the radial dose functional, and the anisotropy function. In addition, to aid the quality control process on treatment planning systems, a two-dimensional (2D) rectangular dose rate table (the traditional along-away table), coherent with the TG43 dose calculation formalism, is given. The data given in this study complement existing information for both sources on the following aspects: (i) the source asymmetries were considered explicitly in the Monte Carlo calculations, (ii) TG43 data were derived directly from Monte Carlo calculations, (iii) the radial range of the different tables was increased as well as the angular resolution in the anisotropy function, including angles close to the longitudinal source axis. The CSM2 source TG-43 data of Liu et al. [Med. Phys. 31, 477-483 (2004)] are not consistent with the Williamson 2D along-away data [Int. J. Radiat. Oncol., Biol., Phys. 15, 227-237 (1988)] at distances closer than approximately 2 cm from the source. The data presented here for this source are consistent with this 2D along-away table, and are suitable for use in clinical practice.
在本研究中，使用蒙特卡罗GEANT4代码获得了CSM2和CSM3铯 - 137源的完整剂量数据集。该计算方法的应用通过热释光剂量测定法（TLD）进行了实验验证。给出了遵循TG43形式主义的函数和参数：剂量率常数、径向剂量函数和各向异性函数。此外，为了辅助治疗计划系统的质量控制过程，给出了一个与TG43剂量计算形式主义相一致的二维（2D）矩形剂量率表（传统的沿 - 离表）。本研究给出的数据在以下方面补充了这两种源的现有信息：（i）在蒙特卡罗计算中明确考虑了源的不对称性；（ii）TG43数据直接从蒙特卡罗计算得出；（iii）不同表格的径向范围以及各向异性函数中的角度分辨率都有所增加，包括靠近源纵向轴的角度。Liu等人[《医学物理》31, 477 - 483 (2004)]给出的CSM2源的TG - 43数据与Williamson的二维沿 - 离数据[《国际放射肿瘤学、生物学、物理学杂志》15, 227 - 237 (1988)]在距离源约2 cm以内不一致。此处给出的该源数据与这个二维沿 - 离表一致，适用于临床实践。
