Video-rate optical dosimetry and dynamic visualization of IMRT and VMAT treatment plans in water using Cherenkov radiation
Video-rate optical dosimetry and dynamic visualization of IMRT and VMAT treatment plans in water using Cherenkov radiation
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DOI：
10.1118/1.4875704
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发表时间：
2014-06-01
期刊：
影响因子：
3.8
通讯作者：
Gladstone, David J.
中科院分区：
文献类型：
--
作者：
Glaser, Adam K.;Andreozzi, Jacqueline M.;Gladstone, David J.
目的：首次研究了动态调强放射治疗（IMRT）和容积调强弧形放射治疗（VMAT）计划的光学剂量测量新技术，即通过捕获水中感生切伦科夫辐射的图像。配置高灵敏度增强CCD相机（ICCD）以获取由IMRT和VMAT计划引起的切伦科夫辐射的二维（2D）投影图像，基于任务组119（TG-119）C形几何形状。使用Varian Eclipse治疗计划系统（TPS）生成计划，并使用来自Varian TrueBeam直线加速器（Linac）的6 MV X射线入射到掺杂有荧光团硫酸奎宁的水箱上。ICCD采集选通到直线加速器目标触发脉冲以减少背景光伪影，读出单个辐射脉冲，并合并到512 x 512像素的分辨率。由此产生的视频进行了分析，时间为各种区域的兴趣（ROI），覆盖计划靶体积（PTV）和器官的风险（OAR），并总结，以获得一个整体的光强度分布，这是比较预期的剂量分布从TPS使用伽玛指数analysis.Results：所选择的相机设置导致每秒23.5帧的剂量测定视频。PTV和OAR ROI的时间强度图证实了PTV相对于OAR的优先剂量输送，并且伽马分析分别在实验捕获的切伦科夫光分布和基于3%/3 mm剂量差和距离一致性标准的预期TPS剂量分布之间产生了95.9%和96.2%的一致性。这项初步研究的结果表明，首次记录使用切伦科夫辐射的视频速率光学剂量测定的动态IMRT和VMAT治疗计划。所提出的方式有几个潜在的优势，包括收购的实时性的替代方法，并在未来的完善可能会被证明是一个强大的和新颖的剂量测定方法与研究和临床应用。c 2014年美国医学物理学家协会。
Purpose: A novel technique for optical dosimetry of dynamic intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) plans was investigated for the first time by capturing images of the induced Cherenkov radiation in water.Methods: A high-sensitivity, intensified CCD camera (ICCD) was configured to acquire a two-dimensional (2D) projection image of the Cherenkov radiation induced by IMRT and VMAT plans, based on the Task Group 119 (TG-119) C-Shape geometry. Plans were generated using the Varian Eclipse treatment planning system (TPS) and delivered using 6 MV x-rays from a Varian TrueBeam Linear Accelerator (Linac) incident on a water tank doped with the fluorophore quinine sulfate. The ICCD acquisition was gated to the Linac target trigger pulse to reduce background light artifacts, read out for a single radiation pulse, and binned to a resolution of 512 x 512 pixels. The resulting videos were analyzed temporally for various regions of interest (ROI) covering the planning target volume (PTV) and organ at risk (OAR), and summed to obtain an overall light intensity distribution, which was compared to the expected dose distribution from the TPS using a gamma-index analysis.Results: The chosen camera settings resulted in 23.5 frames per second dosimetry videos. Temporal intensity plots of the PTV and OAR ROIs confirmed the preferential delivery of dose to the PTV versus the OAR, and the gamma analysis yielded 95.9% and 96.2% agreement between the experimentally captured Cherenkov light distribution and expected TPS dose distribution based upon a 3%/3 mm dose difference and distance-to-agreement criterion for the IMRT and VMAT plans, respectively.Conclusions: The results from this initial study demonstrate the first documented use of Cherenkov radiation for video-rate optical dosimetry of dynamic IMRT and VMAT treatment plans. The proposed modality has several potential advantages over alternative methods including the real-time nature of the acquisition, and upon future refinement may prove to be a robust and novel dosimetry method with both research and clinical applications. c 2014 American Association of Physicists in Medicine.