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治疗治疗癌症的兴趣日益增加，独立研究预计安装基数每年增加20%。用质子治疗代替X射线治疗，由于大大降低了长期和短期的毒副作用，将对患者产生实质性的长期益处。这些影响还具有与其治疗相关的大量费用，这些费用可能在治疗后持续多年。使提供质子治疗的成本与X射线治疗的成本相比具有竞争力，不仅使上级治疗模式可用，而且还将为健康护理提供者带来大量的长期节省。现存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，其中小束3D点（体素）的扫描利用质子的物理性质并提供最终的肿瘤适形性，现在正被快速引入用于剂量递送。SBS消除了对患者特定设备（准直器和补偿器）的需要，这些设备制造昂贵并且显著增加了向患者递送每个剂量所需的时间，从而进一步降低了操作成本。然而，SBS方法对器官运动比传统程序更敏感。为了克服靶体积的这种快速SBS，将剂量输送时间大大减少到毫秒（ms）时间尺度是最佳的。Phenix认为，快速扫描不仅使SBS更适合治疗移动目标，而且还可以根据使用质子的新前瞻性治疗方案（如肺肿瘤）的需要实现更快的剂量输送。供应商越来越多地使用加速器，以短ms脉冲输送光束，这对检测器提出了进一步的挑战，而不是快速验证治疗区域和输送到肿瘤的剂量大小。这些双重挑战需要检测器，其可以实时监测位置和输送的剂量，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。本资助申请的具体目标是进行进一步开发使用新型快速气体闪烁技术所需的研究，以基于第一阶段开发的原型在亚毫秒时间尺度上测量输送的剂量和光斑位置。

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.