Dose Imaging Detectors for Radiotherapy Based on Gas Electron Multipliers

描述（由申请人提供）： 在这个SBIR项目中，PartTec将开发一种探测器，可以支持下一代质子治疗强度调制质子治疗的高精度要求。目前还没有探测器能够满足该项目的设计目标，特别是高空间和时间分辨率。虽然已经开始在这一领域作出努力，但没有商业上可替代本提案所预期的探测器。40多年来，质子治疗的精度不断提高。质子治疗提供了上级肿瘤控制，并大大减少了治疗后的副作用相比，传统的外部束治疗，手术和化疗。由于这些实质性的好处，质子治疗是一种重要的放射治疗选择。大多数实体瘤，特别是那些位于关键结构附近的实体瘤，可以用质子治疗。质子治疗的上级剂量分布允许对以前没有选择的患者进行治疗，例如患有复发性癌症的患者或不再能够耐受其他治疗的患者。大约50%的儿童接受质子治疗后，继发性恶性肿瘤的发生率降低，神经心理和智力缺陷的风险降低。拟议的项目高度集中于生产一种探测器，以满足肿瘤学家，医学物理学家，剂量学家和治疗师的当前需求，他们正在为患者提供质子治疗。质子治疗发展的下一步是强度调制质子治疗（IMPT）。这项创新使用质子束的“笔形束”扫描穿过肿瘤，从一侧到另一侧，从上到下。同时，控制射束穿透的深度，使其能量能够沉积到肿瘤内非常小的三维体素中。传统的质子治疗设施与被动束扩散和均匀扫描束也将受益于开发新的，高精度的检测器，在线束监测和质量保证。在该提案的第一阶段，PartTec将开发一种创新的位置敏感气体电子倍增器（GEM）探测器系统，用于粒子治疗中的二维剂量成像。PartTec认为，如果用作深度剂量剖面仪，这种探测器将能够提供线性响应，优于1毫米的空间分辨率，微秒的时间分辨率和布拉格峰形状的准确再现。GEM在检测器设计中提供了快速的性能、稳健性和灵活性，允许各种拾取电极布局和级联GEM的选项，以提高信噪比。根据测量要求，2D读出将使用CCD相机或分段拾取电极和电荷积分前端电子器件进行。在该提案的第二阶段，PartTec的研究将扩展到包括这种探测器的深度剂量（3D）分析能力。公共卫生相关性：所有医疗提供者都希望为患者提供最好、最精确和最安全的癌症治疗。希望是放射治疗，摧毁癌细胞，同时避免伤害非癌细胞。质子治疗，特别是强度调制质子治疗（IMPT），提供了希望。沿着治疗递送方法的发展，需要新一代的检测器来监测和报告质子束的精确对准。在这个SBIR项目中，PartTec，Ltd.将开发这样一种光束探测器，以扩大和改善公众的整体治疗选择。

DESCRIPTION (provided by applicant): In this SBIR project, PartTec will develop a detector that can support the high precision requirements of Intensity Modulated Proton Therapy, the next-generation Proton Therapy. There are no detectors currently available that meet the design goals of this project, in particular high spatial and timing resolution. While efforts have been started in this area, there is no commercially available alternative to the detector anticipated by this proposal. Proton therapy has been offered with ever-increasing precision for more than 40 years. Proton therapy provides superior tumor control and vastly diminishes post-treatment side effects when compared to conventional external beam therapies, surgery and chemotherapy. Because of these substantial benefits, proton therapy is an important radiation therapy treatment option. Most solid tumors, particularly those located near critical structures, can be treated with proton therapy. The superior dose distribution of proton therapy allows treatment for patients for whom there was previously no option such as patients with recurrent cancers or patients who can no longer tolerate other therapies. Approximately 50% of children treated with proton therapy have reduced incidence of secondary malignancies and reduced risk of neuropsychologic and intellectual deficits. The proposed project is highly focused on producing a detector that will meet current needs of the Oncologists, Medical Physicists, Dosimetrists and Therapists who are delivering Proton Therapy to their patients. The next step in the Development of Proton Therapy is the Intensity Modulated Proton Therapy (IMPT). This innovation uses "pencil beam" scanning of the Proton Beam across the tumor, from one side to the other and from top to bottom. At the same time, the depth of the beam penetration is controlled, enabling its energy to be deposited into very small three-dimensional voxels within the tumor. Conventional Proton Therapy facilities with passive beam spreading and uniform scanning beams will also benefit from development of new, high precision detectors for on-line beam monitoring and quality assurance. In Phase I of this proposal PartTec will develop an innovative position sensitive Gas Electron Multiplier (GEM) detector system for two-dimensional dose imaging in particle therapy. PartTec believes such detectors will be capable of providing linear response, better than one millimeter spatial resolution, microsecond time resolution, and accurate reproduction of the Bragg peak shape if used as depth dose profilers. The GEM offers fast performance, robustness and flexibility in the detector design, allowing for various pickup electrode layouts and the option to cascade GEMs in order to improve the signal to noise ratio. Depending on the measurement requirements, 2D readout will be performed with either a CCD camera or segmented pickup electrodes and charge-integrating front-end electronics. In Phase II of this proposal, PartTec's research will be extended to include the depth dose (3D) profiling capabilities o such a detector. PUBLIC HEALTH RELEVANCE: All Medical Providers want to provide their patients with the best, most precise and safe cancer treatments available. The hope is for radiotherapy that destroys cancer cells while avoiding injury to non-cancerous cells. Proton Therapy, especially Intensity Modulated Proton Therapy (IMPT), offers that hope. Along with development of treatment delivery methods, there is the need for a new generation of detectors that monitor and report the precise alignment of the proton beam. In this SBIR project, PartTec, Ltd. will develop such a beam detector that will expand and improve overall treatment options for the public.