Simulation and measurements of HDR brachytherapy source dosimetric parameters using a fiber-optic dosimeter

作者：Khalid Alhamad, Hasham Ahmed, Dean Cutajar, Joel Poder, Anatoly Rosenfeld, Enbang Li · 发表于：Radiation Measurements · 年份：2025 · DOI：10.1016/j.radmeas.2025.107469 · 被引用次数：2 · 研究领域：Advanced Radiotherapy Techniques、Radiation Therapy and Dosimetry、Radiation Detection and Scintillator Technologies

The aim of this study is to evaluate the feasibility of using CsI(Tl)-based fibre-optic dosimetry system for TG-43 dosimetric characterization of the Flexisource 192 Ir HDR brachytherapy source. The investigation focuses on anisotropy and radial dose function measurements and assesses the impact of fluorescence and Cherenkov radiation on signal accuracy, with validation through TOPAS Monte Carlo simulations. Thallium Doped-Caesium Iodide (CsI(Tl)) scintillation crystals were used within a custom-designed PMMA phantom. The experiment, conducted with a Flexitron afterloader and 192 Ir Flexisource, involved measurements at distances of 1.5–6 cm and polar angles of 20°–155°, with increments matching those in the published studies. Comprehensive dosimetric data were collected, revealing the influence of fluorescence and Cherenkov radiation on anisotropy function measurements. The radial dose function showed good agreement with simulation, with minor deviations attributed to limitations in the treatment planning. TOPAS Monte Carlo simulations demonstrated consistent agreement with experimental results, yielding a maximum absolute difference of 0.035 in the experimental data and a maximum deviation of 2.6% in anisotropy function validation against published reference data, further confirming the reliability of both the experimental approach and the simulation model. These findings underscore the importance of accounting for fluorescence and Cherenkov radiation in detector signal res...