Development of real-time dosimetry methods for VHEE FLASH Radiation Therapy

开发 VHEE FLASH 放射治疗的实时剂量测定方法

• 批准号: 2432490
• 金额: --
• 依托单位: University of Oxford
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2020
• 资助国家: 英国
• 起止时间: 2020 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2432490
• 关键词: Development; real; time; dosimetry; methods

Cancer is a critical societal issue. Worldwide, in 2018 alone, 18.1 million cases were diagnosed, 9.6 million people died and 43.8 million people were living with cancer. Current projections anticipate an increase with approximatively 24,6 million newly diagnosed patients and 13 million related deaths by 2030.Ever since the discovery of X-rays in 1895, they played key role in cancer treatment. The beams of high-energy particles are known for depositing their kinetic energy when entering and propagating through matter. In radiotherapy (RT), this property of beams is used for the treatment of tumour's, since the deposited energy can damage and kill the tumour cells. Different particle types have been used for this purpose - photons (most common type of RT), electrons, neutrons, protons and heavy ions. RT is now a fundamental component of effective cancer treatment and control. The most frequently used modality of RT uses high-energy (6 to 10 MeV) photon, and in a small proportion low to intermediate energy (3 to 25 MeV) electron beams. The main challenge of RT is that the dose delivered to a tumour is limited by the dose that can be tolerated by the surrounding normal tissues.On the other hand, conventional photon RT is characterised by almost exponential attenuation and absorption, and consequently delivers the maximum energy near the beam entrance, but continues to deposit significant energy at distances beyond the cancer target. The maximum dose for photons beams with an energy of about 8 MeV, is reached at a depth of 2-3cm of soft tissue. RT is by far the most cost-effective modality for cancer treatment with the added advantage of conserving normal tissue function. The Global Task Force on Radiotherapy for Cancer Control (GTFRCC) estimated that 12,600 megavolt-class treatment machines will be needed to meet demand in LMICs by 2035 (there are currently only 385 machines) .Aims and Objectives.The STELLA (Smart Technologies to Extend Lives with Linear Accelerators) project will identify the fundamental specifications for an advanced X-ray RTT system for application in the challenging environments. A suitable electron-beam accelerator will be developed which matches these requirements, incorporating modern principles and technologies which are able to provide robust operation and modularized implementation.For the accelerator, modular options for the linear accelerator (linac) will be explored, which will be simpler and cheaper to maintain. These will include assessments of; a) The feasibility of a modular electron gun design to be simply separated from the linac structure for easy servicing/replacement to increase reliability and lifetime. b) Novel open linac structure solutions which could be substantially cheaper to manufacture and remove requirement for tuning post manufacturing. c) A new compact RF sources to power the linac, to minimise the physical size of the machine. d) Solutions for turn-key RF systems that is simpler for hospital engineers to replace. e) Ways to minimise the impact of highly variable electricity supply and determine improved methodologies. f) Improved modularity for local control and remote monitoring to predict common failure modes and minimise down time. g) The main causes of failure in RTT systems to perform statistical analysis of data provided by several hospitals in ODA countries. Similar issues are found in the Modulators, Klystrons, RF cavities and electron guns in CLARA at Daresbury and it can be used as a test bed for these studies. The student will work in collaboration with by ASTeC (technical lead for STELLA prototyping).

癌症是一个严重的社会问题。仅在2018年，全球就有1810万例确诊病例，960万人死亡，4380万人患有癌症。目前的预测预计到2030年将增加约2460万新诊断患者和1300万相关死亡。自从1895年发现X射线以来，它们在癌症治疗中发挥了关键作用。众所周知，高能粒子束在进入并穿过物质传播时会沉积其动能。在放射治疗（RT）中，光束的这种特性用于治疗肿瘤，因为沉积的能量可以损伤和杀死肿瘤细胞。不同的粒子类型已用于此目的-光子（最常见的RT类型），电子，中子，质子和重离子。RT现在是有效治疗和控制癌症的基本组成部分。最常用的RT模式使用高能（6至10 MeV）光子，以及小比例的低至中能（3至25 MeV）电子束。放射治疗的主要挑战是，肿瘤所能接受的剂量受到周围正常组织所能承受的剂量的限制。另一方面，传统的光子放射治疗的特点是几乎呈指数衰减和吸收，因此在射束入口附近提供最大能量，但在癌症靶点以外的距离继续存款大量能量。能量约为8 MeV的光子束的最大剂量在2-3cm的软组织深度处达到。RT是迄今为止最具成本效益的癌症治疗方式，具有保留正常组织功能的额外优势。全球癌症控制放射治疗工作组（GTFRCC）估计，到2035年，将需要600兆伏级治疗机来满足中低收入国家的需求（目前只有385台机器）。（智能技术，以延长寿命与线性加速器）项目将确定基本规格的先进的X-射线RTT系统的应用在具有挑战性的环境。一个合适的电子束加速器将符合这些要求，结合现代的原则和技术，能够提供强大的操作和模块化的实施。对于加速器，模块化选项的直线加速器（直线加速器）将被探索，这将是更简单和更便宜的维护。这些将包括评估：a）模块化电子枪设计的可行性，简单地从直线加速器结构中分离出来，便于维修/更换，以提高可靠性和寿命。B）新颖的开放式直线加速器结构解决方案，其制造成本可以大大降低，并且消除了对调谐柱制造的要求。c）为直线加速器供电的新的紧凑型RF源，以最小化机器的物理尺寸。d）用于交钥匙射频系统的解决方案，更易于医院工程师更换。（e）如何尽量减少高度可变的电力供应的影响，并确定改进的方法。f）改进本地控制和远程监控的模块化，以预测常见故障模式并最大限度地减少停机时间。（g）RTT系统无法对官方发展援助国家几家医院提供的数据进行统计分析的主要原因。在达雷斯伯里的AMIA中的调制器、速调管、RF腔和电子枪中也发现了类似的问题，它可以用作这些研究的试验台。学生将与ASTeC（STELLA原型设计的技术负责人）合作。