Mosleh-Shirazi Mohammad Amin, Zarrini-Monfared Zinat, Karbasi Sareh, Zamani Ali
Physics Unit, Department of Radiotherapy and Oncology, Shiraz, Iran ; Radiology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
Department of Medical Physics and Engineering, Shiraz University of Medical Sciences, Shiraz, Iran ; Student Research Committee, Shiraz University of Medical Sciences, Shiraz, Iran.
J Med Phys. 2014 Jan;39(1):18-23. doi: 10.4103/0971-6203.125481.
Two-dimensional (2D) arrays of thick segmented scintillators are of interest as X-ray detectors for both 2D and 3D image-guided radiotherapy (IGRT). Their detection process involves ionizing radiation energy deposition followed by production and transport of optical photons. Only a very limited number of optical Monte Carlo simulation models exist, which has limited the number of modeling studies that have considered both stages of the detection process. We present ScintSim1, an in-house optical Monte Carlo simulation code for 2D arrays of scintillation crystals, developed in the MATLAB programming environment. The code was rewritten and revised based on an existing program for single-element detectors, with the additional capability to model 2D arrays of elements with configurable dimensions, material, etc., The code generates and follows each optical photon history through the detector element (and, in case of cross-talk, the surrounding ones) until it reaches a configurable receptor, or is attenuated. The new model was verified by testing against relevant theoretically known behaviors or quantities and the results of a validated single-element model. For both sets of comparisons, the discrepancies in the calculated quantities were all <1%. The results validate the accuracy of the new code, which is a useful tool in scintillation detector optimization.
厚分段闪烁体的二维（2D）阵列作为用于二维和三维图像引导放射治疗（IGRT）的X射线探测器备受关注。它们的探测过程包括电离辐射能量沉积，随后是光学光子的产生和传输。现有的光学蒙特卡罗模拟模型数量非常有限，这限制了同时考虑探测过程两个阶段的建模研究数量。我们展示了ScintSim1，这是一个在MATLAB编程环境中开发的用于闪烁晶体二维阵列的内部光学蒙特卡罗模拟代码。该代码基于现有的单元素探测器程序进行了重写和修订，具有对具有可配置尺寸、材料等的二维元素阵列进行建模的额外能力。该代码生成并跟踪每个光学光子在探测器元件（以及在串扰情况下，周围元件）中的历史，直到它到达可配置的接收器或被衰减。通过与相关的理论已知行为或量以及经过验证的单元素模型的结果进行测试，验证了新模型。对于两组比较，计算量的差异均<1%。结果验证了新代码的准确性，它是闪烁探测器优化中的一个有用工具。
