Development of functional magnetic resonance imaging-guided adaptive radiotherapy for head and neck cancer patients using novel MR-Linac device

项目摘要/摘要 在保留正常组织的同时向癌症提供剂量是放射治疗的最终目标， 尤其是头部和颈部。通过识别在治疗早期更有可能产生反应的肿瘤，如 以及耐药肿瘤的亚体积，放射治疗计划每天都可以改变，以利用 肿瘤中的生物变化，导致副作用减少，治愈概率相当。功能性 成像技术，如扩散加权成像(DWI)和体素内非相干运动(IVIM)， 在临床系列中证明了区分头颈部放射治疗的早期应答者的有效性 癌症，以及在治疗后识别抗辐射疾病。这些功能成像技术 可用于在放射治疗过程中主动适应高频放射治疗， 不需要外源性对比剂或示踪剂。 德克萨斯大学安德森癌症中心、Elekta医疗系统和飞利浦医疗 正在联合开发一种组合成像/治疗输送设备，它结合了1.5特斯拉MRI和 直线加速器。MR-LINAC设备提供获取功能和解剖成像数据的能力 每天，在治疗位置，同时进行放射治疗。 拟议的项目是一项为期五年的技术发展战略，最终将导致 定量功能成像引导的头部和头部半自动剂量调整的统一工作流程 颈部放射治疗。该项目将实现最先进的同步解剖和DWI图像 采集、空间精确剂量和图像配准、基于物理和数字体模的质量 保证、感兴趣区域累积剂量的软件跟踪、表观扩散的连续跟踪 系数(ADC)图，以及基于解剖和功能成像约束的序列重新优化。最后， 我们将利用来自头颈部癌症MRI临床试验的数据来验证和强化 建议的影像获取/质量保证/软件工作流程，以证明临床可行性 并评估其降低毒性和临床应用的潜力。 该项目的成功完成将产生一种监测功能成像变化的方法 放射治疗期间每天对肿瘤和正常组织进行放射治疗。此方法可用于生成数据以评估 对器官和关键结构的剂量，并可用于最大限度地增加对肿瘤的剂量和/或将其最小化 对正常组织造成并发症的风险。由此得到的数据也可用于研究与剂量相关的治疗。 副作用。利用这项技术的最终目标是改善放射治疗的交付。 以及放射治疗患者的生活质量。

PROJECT SUMMARY/ABSTRACT Delivering dose to cancers while sparing normal tissue is the ultimate goal in radiotherapy treatment, especially in the head and neck. By identifying tumors which are more likely to respond early in treatment, as well as subvolumes of resistant tumor, radiotherapy plans could be changed each day to take advantages of biological alteration in the tumor, resulting in reduced side effects with equivalent probability of cure. Functional imaging techniques, such as diffusion-weighted imaging (DWI) and intravoxel incoherent motion (IVIM), have demonstrated utility in clinical series in discriminating early responders to radiation therapy in head and neck cancers, as well as identifying radiation resistant disease post-therapy. These functional imaging techniques could be utilized to actively adapt radiation therapy with high frequency during the radiation treatment course, without requiring exogenous contrast or tracer administration. The University of Texas M.D. Anderson Cancer Center, Elekta Medical Systems and Philips Healthcare are jointly developing a combination imaging/therapy delivery device, which combines a 1.5 Tesla MRI with a linear accelerator. The MR-LinAc device provides the capacity to acquire functional and anatomic imaging data daily, in the treatment position, while simultaneously delivering radiotherapy. The proposed project is a five-year technology development strategy that will ultimately result in a unified workflow for quantitative functional imaging guided semi-automated dose modification during head and neck radiotherapy. This project will implement state of the art simultaneous anatomic and DWI image acquisition, spatially accurate dose and image registration, physical and digital phantom-based quality assurance, software tracking of cumulative region of interest dose, serial tracking of apparent diffusion coefficient (ADC) maps, and anatomic and functional imaging constraint based serial re-optimization. Finally, we will leverage data from prospective head and neck cancer MRI clinical trials to validate and harden the proposed imaging acquisition/quality assurance/software workflow in order to demonstrate clinical feasibility and estimate potential for toxicity reduction and clinical utility. Successful completion of this project will result in a method for monitoring functional imaging changes to tumor and normal tissue daily during radiotherapy. This method can be used to generate data to assess the dose to the organs and critical structures and can be used to maximize the dose to the tumor and/or minimize the risk of complications to normal tissue. The resulting data can also be used to study dose-related treatment side effects. The ultimate goal of utilizing this technology is to improve the delivery of radiotherapy treatments and the quality of life of radiotherapy patients.