Evaluation of 3D Dose Distribution and Clinical Applications Using Polymer Gel Dosimeter
Evaluation of 3D Dose Distribution and Clinical Applications Using Polymer Gel Dosimeter
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使用聚合物凝胶剂量计评估 3D 剂量分布和临床应用
DOI：
10.11323/jjmp.37.3_165
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
廣川 裕
中科院分区：
文献类型：
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作者：
小野 薫;藤本 幸恵;林 慎一郎;日置 一成;宮沢 正則;赤木 由紀夫;廣川 裕
本文以聚合物凝胶剂量计为例，评价了容积调制式弧形治疗（VMAT）过程中多叶准直器（MLC）运动与肿瘤呼吸运动相互作用的剂量学影响。将填充有聚丙烯酰胺基凝胶剂量计（含有氯化镁作为致敏剂（iPAGAT剂量计））的优良气体屏障PAN（聚丙烯腈）瓶设置为QUASAR™呼吸运动体模（Modus），并在Novalis Tx直线加速器（Varian/BrainLAB）输送VMAT期间以1和2 cm的运动幅度（峰-峰幅度）移动4秒。考虑到呼吸运动和设置的不确定性，定义了两个直径为2 cm的球形GTV和两个PTV。通过3 T MRI系统读取iPAGAT剂量计中的三维（3D）剂量分布，并使用内部开发的软件通过剂量分布、伽马分析和剂量体积直方图（DVH）进行评价。因此，相互作用效应可忽略不计，因为在模拟呼吸运动的VMAT输送过程中，GTV的剂量覆盖范围足够。
Evaluation of dosimetric impact of the interplay effect between multi-leaf collimator (MLC) movement and tumor respiratory motion during volumetric modulated arc therapy (VMAT) delivery using polymer gel dosimeter was taken as an example in this article. An excellent gas barrier PAN (polyacrylonitrile) bottle filled with polyacrylamide-based gel dosimeter contained magnesium chloride as a sensitizer (iPAGAT dosimeter) was set to the QUASAR™ respiratory motion phantom (Modus), and was moved with motion amplitudes (peak-to-peak amplitude) of 1 and 2 cm with a 4 second period during VMAT delivery by the Novalis Tx linear accelerator (Varian/BrainLAB). Two spherical GTVs with 2 cm diameter and two PTVs were defined considering the respiratory motion and setup uncertainties. Three-dimensional (3D) dose distribution in iPAGAT dosimeter was read out by the 3T MRI system, and was evaluated by the dose profiles, gamma analysis and the dose-volume histogram (DVH) using in-house developed software. As a result, interplay effect was negligible since dose coverage of GTV was sufficient during VMAT delivery with simulated respiratory motion.