Development of an ultra-high dose rate rotational linac for FLASH Radiotherapy

开发用于闪光放射治疗的超高剂量率旋转直线加速器

• 批准号: 10773698
• 负责人: Ronald Agustsson
• 金额: $ 74.68万
• 依托单位: UNIVERSITY OF CALIFORNIA, SAN FRANCISCO
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-03-15 至 2026-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10773698
• 关键词: Acceleration; Algorithms; Biological; Cancer Patient; Clinical; Collaborations; Complex; Computer software; Development; Disease; Dose; Dose Rate; Electron Beam; Electrons; Face; Foundations; Human; Intensity modulated proton therapy; Intensity-Modulated Radiotherapy; Linear Accelerator Radiotherapy Systems; Mechanics; Medical; Methods; Modeling; Movement; Normal tissue morphology; Output; Oxygen; Patients; Penetration; Photons; Plant Leaves; Process; Production; Protons; Radiation; Radiation therapy; Radiobiology; Roentgen Rays; Safety; Scanning; Shapes; Speed; Spottings; System; Technology; Testing; Therapeutic; Time; Toxic effect; Treatment Efficacy; Uncertainty; arm; cancer radiation therapy; cell killing; dosimetry; effective therapy; electron energy; image guided radiation therapy; improved; industry partner; neoplastic cell; prevent; proton therapy; research clinical testing; scale up; success; technology development; tissue injury; tumor

Abstract Radiotherapy is used to treat 60% of the cancer patients and 40% of curative cases. However, normal tissue toxicities still prevent radiotherapy from achieving more effective tumor control in many patients despite decades of technological development in intensity-modulated radiation therapy and image-guided radiation therapy. Ultra- high dose rate, a.k.a., FLASH radiotherapy has recently re-emerged as a potential method to significantly improve the radiation biological dose conformality on top of the physical dose conformality. Although existing X- ray linac and proton systems can be modified to deliver the FLASH dose rate, they are limited in either field size, depth penetration, or dose conformality to be useful for treating most human tumors. Conceptual systems such as very high energy electron and PHASER will need to overcome significant and risky technological barriers to be clinically practical. In this Academic-Industrial Partnerships project, we propose to develop a high dose rate X-ray radiotherapy system that is a scale-up of existing technologies for clinical FLASH radiotherapy. There are three major technical challenges in achieving the FLASH dose rate with X-rays. The first is the linear accelerator that is capable to produce such a high dose rate. For this challenge, we hypothesize that a 12 MV X-ray beam >300 Gy/s uncollimated dose rate can be achieved using a combination of already-demonstrated accelerator technologies. The second challenge is the well-separated beam angles for good X-ray dosimetry. The third challenge is intensity modulation for conformal dose distribution. The tightly correlated second and third challenges are due to the slow mechanical movement of the common C-arm gantry and the MLC leaf speed. To overcome these two challenges, we propose to develop a rotational ring-gantry FLASH IMRT platform with many quasi-static MLCs. The fast-spinning ring-gantry system would deliver the entire treatment in an arc within a very short time. The intensity modulation is achieved by using a decoupled MLC ring with a large number of MLC banks each pre-shaping the aperture for rotational IMRT. The system would then be able to achieve highly conformal dose distribution comparable to state of the art VMAT, and at the same time take advantage of the FLASH radiobiology. We propose the following aims: Aim 1. High dose rate linac development; Aim 2. Development of ROtational direct Aperture optimization with a Decoupled (ROAD) MLC ring; Aim 3. Demonstration of rotational FLASH using a benchtop system.

摘要 放射治疗用于治疗60%的癌症患者和40%的治愈病例。然而，正常组织 尽管几十年来，毒副作用仍然阻碍放射治疗在许多患者中实现更有效的肿瘤控制 调强放射治疗和影像引导放射治疗技术发展的最新进展。超强的 高剂量率，也就是闪光放射治疗最近重新成为一种潜在的治疗方法 在物理剂量一致性的基础上，提高辐射生物剂量一致性。尽管现有的X- 射线直线加速器和质子系统可以被修改以提供闪光剂量率，它们在任一场大小中都受到限制， 深度渗透，或剂量一致性，对治疗大多数人类肿瘤有用。概念系统，如 因为超高能电子和相控器将需要克服重大和危险的技术障碍，以 临床上切合实际。在这个学术-产业合作项目中，我们建议开发一个高剂量率 X射线放射治疗系统是对现有临床闪光放射治疗技术的放大。确实有 实现X射线闪光剂量率的三大技术挑战。第一个是直线加速器 能够产生如此高的剂量率。对于这个挑战，我们假设一个12 mV的X射线 使用已经证明的组合可以获得射束&GT；300GY/S的非准直剂量率 加速器技术。第二个挑战是良好的X射线剂量测量所需的良好分离的光束角度。 第三个挑战是适形剂量分布的强度调制。紧密相关的第二和第三 挑战是由于普通C形臂龙门的机械运动缓慢和MLC叶片速度。至 克服这两个挑战，我们建议开发一种旋转式环架闪光调强放疗平台，具有多个 准静态MLC。快速旋转的环式龙门架系统将在一个非常短的时间内提供整个处理过程 做爱。强度调制是通过使用具有大量MLC的去耦合MLC环来实现的 每个组都预塑了旋转调强放射治疗的光圈。然后，该系统将能够实现高度 与最先进的VMAT相当的保形剂量分布，同时利用 闪光放射生物学。我们提出了以下目标：目标1。高剂量率直线加速器的研制；目标2。 发展解耦(道路)MLC环的旋转直接孔径优化；目标3。 使用台式系统演示旋转闪光灯。