Novel, full 3D scintillation dosimetry using a static plenoptic camera
Novel, full 3D scintillation dosimetry using a static plenoptic camera
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DOI：
10.1118/1.4884036
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发表时间：
2014-08-01
期刊：
影响因子：
3.8
通讯作者：
Archambault, Louis
中科院分区：
文献类型：
--
作者：
Goulet, Mathieu;Rilling, Madison;Archambault, Louis
目的：使用3D剂量计进行动态放射治疗输送的患者特定质量保证（QA）。然而，诸如凝胶的3D剂量计具有限制质量保证的许多缺点，诸如繁琐的读出程序和差的再现性。这项工作的目的是开发和验证一种新型的高分辨率3D剂量计的基础上，使用全光相机的塑料闪烁体体积的实时光采集。该剂量计将允许动态放射治疗技术的QA，例如强度调制放射治疗（IMRT）或体积调制弧形治疗（VMAT）。方法：使用Raymet R5全光相机以每秒一次采集的速率对嵌入丙烯酸体模内的10 x 10 x 10 cm（3）EJ-260塑料闪烁体成像。在Clinac iX直线加速器上采用IMRT和VMAT治疗计划对闪烁体进行辐照。使用迭代重建算法，通过对光场相机的每个像素收集的光进行反向投影，在所有维度上以2 mm分辨率重建闪烁体体积发射的3D光分布。后者受到使用与直线加速器集成的射野成像仪获取的入射剂量的射束的眼睛视图投影的约束，并受到作为体模中深度函数的剂量行为的物理考虑的约束。重建的3D剂量与使用治疗计划软件Pinnacle（3）计算的预期剂量之间的绝对剂量差异平均低于1.5%的最大剂量的整合IMRT和VMAT交付，并低于3%的每个单独的IMRT发生率。重建的3D剂量和辐射变色膜采集在同一实验体模之间的剂量协议平均在2.1%和1.2%的最大记录剂量的IMRT和VMAT delivery.Conclusions：使用全光相机技术，作者能够执行毫米分辨率，水当量剂量的IMRT和VMAT计划在整个3D体积。由于剂量计中不需要移动部件，因此可以获取作为时间函数的入射剂量分布，从而能够验证光子、电子和较重离子的静态和动态辐射递送。(C)2014年美国医学物理学家协会。
Purpose: Patient-specific quality assurance (QA) of dynamic radiotherapy delivery would gain from being performed using a 3D dosimeter. However, 3D dosimeters, such as gels, have many disadvantages limiting to quality assurance, such as tedious read-out procedures and poor reproducibility. The purpose of this work is to develop and validate a novel type of high resolution 3D dosimeter based on the real-time light acquisition of a plastic scintillator volume using a plenoptic camera. This dosimeter would allow for the QA of dynamic radiation therapy techniques such as intensity-modulated radiation therapy (IMRT) or volumetric-modulated arc therapy (VMAT).Methods: A Raytrix R5 plenoptic camera was used to image a 10 x 10 x 10 cm(3) EJ-260 plastic scintillator embedded inside an acrylic phantom at a rate of one acquisition per second. The scintillator volume was irradiated with both an IMRT and VMAT treatment plan on a Clinac iX linear accelerator. The 3D light distribution emitted by the scintillator volume was reconstructed at a 2 mm resolution in all dimensions by back-projecting the light collected by each pixel of the light-field camera using an iterative reconstruction algorithm. The latter was constrained by a beam's eye view projection of the incident dose acquired using the portal imager integrated with the linac and by physical consideration of the dose behavior as a function of depth in the phantom.Results: The absolute dose difference between the reconstructed 3D dose and the expected dose calculated using the treatment planning software Pinnacle(3) was on average below 1.5% of the maximum dose for both integrated IMRT and VMAT deliveries, and below 3% for each individual IMRT incidences. Dose agreement between the reconstructed 3D dose and a radiochromic film acquisition in the same experimental phantom was on average within 2.1% and 1.2% of the maximum recorded dose for the IMRT and VMAT delivery, respectively.Conclusions: Using plenoptic camera technology, the authors were able to perform millimeter resolution, water-equivalent dosimetry of an IMRT and VMAT plan over a whole 3D volume. Since no moving parts are required in the dosimeter, the incident dose distribution can be acquired as a function of time, thus enabling the validation of static and dynamic radiation delivery with photons, electrons, and heavier ions. (C) 2014 American Association of Physicists hi Medicine.