A rapid response detector system for intensity modulated proton therapy dosimetry

描述(申请人提供)：近年来，世界各地对使用质子放射疗法治疗癌症的兴趣与日俱增，独立研究计划安装基础每年增加20%。用质子治疗取代X射线治疗将大大减少长期和短期的毒副作用，对患者有很大的长期好处。这种影响也有与其治疗相关的巨额费用，这些费用可能在治疗后持续多年。使质子治疗的成本与X射线治疗相比具有竞争力，不仅可以提供一种更好的治疗模式，而且还将为医疗保健提供者带来大量的长期节省。现有系统的资本和运营成本是一个主要的限制因素。被称为点束扫描(SBS)的过程，其中对小束3D点(体素)的扫描利用了质子的物理性质，并提供了最终的肿瘤整合性，现在正迅速被引入用于剂量输送。SBS消除了对患者专用设备(准直器和补偿器)的需求，这些设备的制造成本很高，并大大增加了向患者提供每剂药物所需的时间，从而进一步降低了运营成本。然而，SBS方法对器官运动比传统方法更敏感。为了克服这种快速的靶区SBS，将剂量传递时间大大减少到毫秒(Ms)的时间尺度是最佳的。菲尼克斯认为，快速扫描不仅使SBS更适合于治疗移动的目标，而且还可以根据使用质子的新的前瞻性治疗方案(如肺部肿瘤)所需的更快的剂量传递。供应商越来越多地使用加速器来提供短毫秒脉冲的束流，这对探测器提出了更多的挑战，而不是快速验证治疗的区域和向肿瘤提供的剂量的大小。这些双重挑战要求探测器能够实时监测输送的位置和剂量，并向加速器提供快速反馈，以根据需要修改要输送的进一步剂量。现有的系统都不能满足这些要求。这项赠款申请的具体目的是进行所需的研究，以进一步开发一种新的非常快速的气体闪烁技术，以第一阶段开发的原型为基础，在亚毫秒级的时间尺度上测量所提供的剂量和光斑位置。

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.