A Coaxial Plasma Accelerator for Proton Radiotherapy

描述（由申请人提供）：质子放射治疗在美国和世界各地正在增长。这种增长是由于质子的商业可用性和改善的将大部分辐射剂量存款在肿瘤中的能力的物理优势，而不是将大部分剂量储存在正常组织中的X射线。在美国，目前有五个质子治疗中心治疗患者和超过2300个基于X射线的线性加速器设施。限制质子放射治疗在一般癌症患者社区的广泛应用的是与质子放射治疗相关的资本、建筑和运营成本，每个站点超过1亿美元，与基于X射线的设施有很大的成本差异。一种引人注目的方法是将质子治疗的物理优势联合收割机结合到一个更小、更便宜的机架安装或固定线系统中，该系统可以广泛传播以改善放射治疗。这种方法使用同轴等离子体质子加速的发展和调查，在这个建议中描述。斯坦福大学等离子体物理实验室最近在等离子体加速器中对一种特殊高速操作模式的理解和稳定方面取得了突破，从而产生了一种加速器概念，这种概念有可能使负担得起的紧凑型质子治疗成为可能。本可行性研究的目的是发展现有的加速器：1。测试和光束表征：该任务包括使用各种光学诊断和使用磁扇区能谱仪测量相空间特性。核径迹探测被用作一种应急措施，用于在广泛的操作条件下表征束流。2.增加等离子体加速器束能量：该任务包括优化和缩放各种参数，例如电极形状和尺寸、电路参数、质量流量和电源电压。这项任务还包括开发一种新的氢气喷射系统。3.束流动力学建模：使用Geant 4软件评估了使用紧凑型磁体/准直器组件进行能量分散和选择的可行性。目标是研究束流传输和准直的方法，同时最大限度地减少和捕获有害的二次辐射和中子。该项目的长期目标是开发下一代质子治疗设备，通过广泛传播紧凑的单室质子治疗系统来改善人类健康。 公共卫生相关性：该提案描述了一个高影响、高风险的发展，结合了斯坦福大学机械工程加速器技术的令人兴奋的前沿发展和放射肿瘤学中一个重要的未满足的需求-一个相对紧凑、廉价的质子治疗加速器。该项目的长期目标是开发下一代质子治疗装置，通过广泛传播小型单间质子治疗系统，改善癌症患者的人类健康，从而增加这种改进的治疗方式的使用。

DESCRIPTION (provided by applicant): Proton radiotherapy is growing in the US and around the world. This growth is due to the commercial availability of protons and the physical advantages of the improved ability to deposit most of the radiation dose in the tumor, as opposed to x-rays where most of the dose is deposited in normal tissues. In the US there are currently five proton therapy centers treating patients and over 2300 x-ray based linear accelerator facilities. Limiting the widespread application of proton radiotherapy to the general cancer patient community is the capital, building and operating costs associated with proton radiotherapy that exceed $100 million per site, a substantial cost differential with x-ray based facilities. A compelling approach is to combine the physical advantages of proton therapy into a smaller, cheaper, gantry-mounted or fixed line system that can be widely disseminated for improved radiotherapy. The development and investigation of such an approach using coaxial plasma proton acceleration, is described in this proposal. Recent breakthroughs in the understanding and stabilization of a special high-velocity mode of operation in plasma accelerators by the Plasma Physics Laboratory at Stanford University have lead to an accelerator concept with the potential to make affordable, compact proton therapy possible. The aims for this feasibility study are to develop the existing accelerator to: 1. Testing and beam characterization: This task includes the use of various optical diagnostics and the measurements of phase space properties using a magnetic sector energy spectrometer. Nuclear track detection is used as a contingency to characterize the beam over a wide range of operating conditions. 2. Increase plasma accelerator beam energy: This task consists of optimization and scaling of various parameters, such as electrode shapes and dimensions, electric circuit parameters, mass flow, and power supply voltage. This task also includes the development of a new hydrogen injection system. 3. Modeling of beam dynamics: The feasibility of using a compact magnet/collimator assembly for energy dispersion and selection is assessed using the Geant4 software. The goal is to study approaches for beam transport and collimation while minimizing and capturing harmful secondary radiation and neutrons. The long term goal of this project is to develop the next generation of proton therapy treatment units that will improve human health through the wide dissemination of a compact, single room, proton therapy treatment system. PUBLIC HEALTH RELEVANCE: This proposal describes a high-impact, high risk development combining exciting cutting edge developments in accelerator technology in mechanical engineering at Stanford University with an important unmet need in radiation oncology- a relatively compact, inexpensive accelerator for proton therapy. The long term goal of this project is to develop the next generation of proton therapy treatment units that will improve human health of cancer patients by the wide dissemination of a small, single room, proton therapy treatment system that will allow increased access to this improved treatment modality.