论文标题
更新低能近距离放射治疗的CLRP TG-43参数数据库
Update of the CLRP TG-43 parameter database for low-energy brachytherapy sources
论文作者
论文摘要
目的：更新Carleton放疗物理学实验室（CLRP）TG-43剂量测定数据库，用于低功能（<50 keV）光子发射低剂量率（LDR）黄胚疗法来源，使用开放式EGSNRC应用程序EGS_BRACHY而不是使用clrp sellr clrp，以前使用的是27 ldr的27 ldr。 （CLRPV1）。 CLRPV2涵盖40个来源（PD-103，I-125，CS-131）。计算了一组全面的TG-43参数，包括剂量率常数，具有功能拟合参数的径向剂量函数，1D和2D各向异性函数，沿量的剂量速率表，一级分解分离剂量表（对于某些来源）以及平均光子能量。该数据库还记录了将成为EGS_BRACHY分布的一部分的源模型。方法：使用EGS ++几何包及其EGS_BRACHY扩展程序对源几何形状进行系统重编码后，计算数据集。在圆柱坐标中具有不同体素分辨率的全散射水幻像用于剂量计算。 EGS_BRACHY中实现了与近距离放射治疗源重叠的幻影体素源校正的新统计不确定性，并且所有CLRPV2数据都包括这些不确定性。为了进行验证，将数据与CLRPV1和文献中的其他数据进行比较。数据访问/格式：可在https://physics.carleton.ca/ clrp/egs_brachy/seed_database_v2上获得数据。除了与先前的计算比较以图形方式呈现外，还可以在Excel（.xlsx）电子表格中为每个源提供数据。应用程序：数据库具有研究，剂量法和近距离放射治疗计划中的应用程序。这项全面的更新为医学物理社区提供了更准确的TG-43剂量评估参数，以及与EGS_BRACHY分发的完全基准的源模型。
PURPOSE: To update the Carleton Laboratory for Radiotherapy Physics (CLRP) TG-43 dosimetry database for low-energy (< 50 keV) photon-emitting low-dose rate (LDR) brachytherapy sources utilizing the open-source EGSnrc application egs_brachy rather than the BrachyDose application used previously for 27 LDR sources in the 2008 CLRP version (CLRPv1). CLRPv2 covers 40 sources (Pd-103, I-125, Cs-131). A comprehensive set of TG-43 parameters is calculated, including dose-rate constants, radial dose functions with functional fitting parameters, 1D and 2D anisotropy functions, along-away dose-rate tables, Primary-Scatter separation dose tables (for some sources), and mean photon energies. The database also documents the source models which will become part of the egs_brachy distribution. METHODS: Datasets are calculated after a systematic recoding of the source geometries using the egs++ geometry package and its egs_brachy extensions. Full scatter water phantoms with varying voxel resolutions in cylindrical coordinates are used for dose calculations. New statistical uncertainties of source volume corrections for phantom voxels which overlap with brachytherapy sources are implemented in egs_brachy, and all CLRPv2 data include these uncertainties. For validation, data are compared to CLRPv1 and other data in the literature. DATA ACCESS/FORMAT: Data are available at https://physics.carleton.ca/ clrp/egs_brachy/seed_database_v2. As well as being presented graphically in comparisons to previous calculations, data are available in Excel (.xlsx) spreadsheets for each source. APPLICATIONS: The database has applications in research, dosimetry, and brachytherapy planning. This comprehensive update provides the medical physics community with more accurate TG-43 dose evaluation parameters, as well as fully-benchmarked source models distributed with egs_brachy.
