A rapid response detector system for intensity modulated proton therapy dosimetry

描述（由申请人提供）：近年来，全世界对使用质子放射疗法治疗癌症的兴趣越来越大，独立研究项目的安装基数每年增加20%。质子治疗代替x射线治疗对患者有长期的好处，因为它大大减少了长期和短期的毒副作用。这些影响也会带来与治疗相关的大量费用，这些费用可能在治疗后持续多年。使质子治疗的成本与x射线治疗的成本具有竞争力，不仅可以提供一种优越的治疗模式，而且还可以为医疗保健提供者节省大量的长期费用。现有系统的资金和运行成本是一个主要的限制因素。该过程被称为点束扫描（SBS），其中扫描小束3D点（体素）利用质子的物理特性，并提供最终的肿瘤一致性，现在正在迅速引入用于剂量传递。SBS消除了对特定于患者的设备（准直器和补偿器）的需求，这些设备不仅制造成本高昂，而且大大增加了向患者提供每次剂量所需的时间，从而进一步降低了操作成本。然而，SBS方法比传统方法对器官运动更敏感。为了克服这一快速靶体积的SBS，将剂量递送时间大大缩短到毫秒（ms）的时间尺度是最理想的。Phenix认为，快速扫描不仅使SBS更适合于治疗移动目标，而且还可以根据新的前瞻性质子治疗方案（如肺肿瘤）的需要，实现更快的剂量递送。供应商越来越多地使用以短毫秒脉冲传输光束的加速器，这给探测器带来了进一步的挑战，而不是快速验证治疗区域和传递给肿瘤的剂量大小。这些双重挑战需要能够实时监测位置和剂量的探测器，并向加速器提供快速反馈，以根据需要修改进一步的剂量。现有的系统都不能满足这些要求。这项拨款申请的具体目的是进行所需的研究，以进一步开发使用一种新型的非常快速的气体闪烁技术，以亚毫秒的时间尺度测量所输送的剂量和基于第一阶段开发的原型的斑点位置。

DESCRIPTION (provided by applicant): In recent years there has been increased interest throughout the world in the use of proton radiation therapy for treatment of cancer and independent studies project a 20% annual increase in the installed base. The replacement of X-ray therapy with proton therapy will have substantial long term benefit to patients due to greatly reduced long and short term toxicity side effects. Such effects also have substantial costs associated with their treatment that may continue for many years after treatment. Making the cost of delivering proton therapy cost competitive to that of X-ray therapy not only makes a superior treatment mode available, but will also result in substantial long term savings to health care providers. The capital and operating cost of extant systems is a major limiting factor. The procedure referred to as Spot Beam Scanning (SBS), where scanning of a small beam 3D spot (voxel) takes advantage of the physical properties of protons and provides the ultimate in tumor conformality is now rapidly being introduced for use in for dose delivery. SBS eliminates the need for patient-specific devices (collimators and compensators) that are both expensive to manufacture and add considerably to the time needed to deliver each dose to the patient, thereby further reducing operating costs. The SBS approach however is more sensitive to organ motion than traditional procedures. To overcome this fast SBS of the target volume to greatly reduce dose delivery times into the millisecond (ms) time scale is optimal. Phenix believes that fast scanning not only makes the SBS more suitable for treating moving targets but also enables faster dose delivery as needed for new prospective treatment protocols using protons, such as lung tumors. The increasing use of accelerators by vendors that deliver beam in short ms pulses places further challenges on detectors than can rapidly verify the area treated and the magnitude of the dose delivered to the tumor. These dual challenges require detectors that can monitor both the position and dose delivered in real-time and provide rapid feedback to the accelerator to modify further dose to be delivered as required. None of the extant systems now available can satisfy these demands. The Specific Aims in this grant application are to perform the research needed to further develop the use of a novel very fast gas scintillation technique to measure the dose delivered and the spot position on a sub-millisecond time scale based on the prototype developed in Phase I.