Very High Energy Electron (VHEE) Radiotherapy: Image Guidance and Dose Delivery

放射治疗依赖于将一定量的剂量(足以杀死肿瘤)准确地输送到正确的位置。为此，现代放射治疗设备具有广泛的质量保证，并结合了先进的图像引导能力。VHEE(甚高能电子)放射治疗(能量范围为~70至250 MeV)目前正在开发中，并有望通过电磁导向电子束快速提供剂量。由于能量高，给药对距离不敏感，因此，即使在身体的不均匀部位，它也普遍适用。它也有可能比目前使用的放射治疗设备便宜得多。此外，VHEE具有极快和大剂量输送到癌症组织的潜力。它还能够利用最近的活体“闪光”研究--其中高剂量极快地输送到组织--允许完全根除肿瘤，同时有望降低影响正常组织的早期和晚期并发症的发生和严重程度。这个项目需要探索将VHEE治疗与绝对剂量测量和图像指导相结合的可行性。快速剂量传递(几秒内)的优势使剂量测量和图像引导变得更加复杂，因为肿瘤的定位必须在类似的时间框架内进行。在未来的VHEE放射治疗的实际应用中，这两个问题都必须解决。在本项目中，我们将研究：1患者运动对闪光投射后影像引导的影响。这与VHEE和质子有关。2将治疗时间与精度要求联系起来。3探索基于平板成像的体内剂量测定。随着项目的进展，我们预计将与临床医生和临床科学家密切合作。该项目有可能开发一种新的放射治疗模式：需要通过高能电子束向患者快速提供非常高剂量的药物。这个项目的重点是图像指导和剂量传递--这两个基本要素是目前研究中所缺乏的，但对于VHEE设施的实用性是不可或缺的。与克里斯蒂NHS信托基金这一领域的专家的合作对该项目很重要，使用GEANT4进行剂量传递的模拟以及克里斯蒂NHS信托基金和欧洲核子研究中心的实验对这项研究的成功很重要。

Radiotherapy depends on accurate delivery of a certain amount of dose (enough to kill the tumour) to the right place. For this purpose modern radiotherapy equipment has extensive QA and is combined with advanced image guidance capabilities.VHEE (Very High Energy Electron) radiotherapy (in the energy range of ~70 to 250 MeV) is currently under development and promises rapid delivery of dose by means of electromagnetically steered e-beams. Because of the high energy, the delivery is range-insensitive and hence it is generally applicable even in inhomogeneous parts of the body. It also has the potential to be significantly cheaper than radiotherapy equipment in use at present.Furthermore VHEE has the potential for extremely rapid and large dose delivery to cancerous tissue. It is also able to take advantage of recent in vivo "FLASH" studies -in which a high dose is delivered to tissue extremely rapidly -allowing complete eradication tumours while promising reduction in the occurrence and severity of early and late complications affecting normal tissue. This studentship entails exploring the feasibility of integrating VHEE therapy with absolute dose measurement, and image guidance. The advantage of rapid dose delivery (within seconds), makes dose measurement more complicated, and also image guidance, because localisation of the tumour has to be performed in a similar timeframe.In a future practical application of VHEE radiotherapy, both issues must be addressed. In this project we will study:1 Effect of patient motion on image guidance followed by flash delivery. This is relevant for VHEE as well as protons.2 Relate treatment time to accuracy requirements.3 Explore in-vivo dosimetry based on flat panel imagers.As the project progresses we anticipate a close collaboration with clinicians and clinical scientists developing. This project has the potential to develop a new paradigm in radiotherapy: entailing rapid delivery of very high doses to patients via high energy electron beams. There is a focus in this project on image guidance and dose delivery -two essential elements that have been lacking from current studies but are integral to the practicality of VHEE facility. The collaboration with experts in this field from the Christie NHS Trust is important to this project Simulation of dose delivery with GEANT4 and experiments at the Christie NHS Trust, and CERN are important to the success of this research.