Motion management for real-time adaptive MRgRT in liver and rectal cancer

肝癌和直肠癌实时自适应 MRgRT 的运动管理

• 批准号: 438106095
• 负责人: Dr. Cihan Gani
• 金额: --
• 依托单位: Radiologische Universitätsklinik (Department)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2020
• 资助国家: 德国
• 起止时间: 2019-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/438106095?language=en
• 关键词: Motion; management; real; time; adaptive

The aim of this project is to investigate tumour motion during irradiation (intrafraction) and between fractions (interfraction) at the hybrid 1.5 T MR-Linac system. Such a hybrid device may facilitate the development of novel and innovative treatment strategies by individualized dose prescriptions based on both anatomical and functional MRI. This is particularly interesting in liver tumors where the surrounding healthy liver tissue is often dose limiting and in rectal tumors when dose escalation is planned in order to increase complete response rates and facilitate organ preservation. However both tumor sites are moving targets due to respiration (liver) or changes of rectal and bladder filling. Thus, a pre-requisite for highly precise individualized dose prescriptions is the assessment of the intrafractional and interfracional tumor motion. In this project we will establish an optimized four-dimensional imaging protocol for the 1.5 T MR-Linac with both anatomical and functional imaging sequences. Based on this we will develop a 4D-response-adaptive protocol for stereotactic body radiotherapy (SBRT) of liver tumors. The idea is to individualize the dose prescription based on the risk of the development of radiation induced liver disease (RILD) and the response seen on anatomical and functional imaging between fractions. For rectal cancer the goal is to assess intrafractional and interfractional motion of the entire tumour and of potential subvolumes that might serve as targets for a “bioBoost”. This bioBoost subvolume is defined by changes observed on diffusion weighted imaging which has already been shown to be predictive of tumor regression. In this project we will further refine these models with the available imaging data assessed through the course of treatment and test different bioBoost strategies such as a sequential boost or a stereotactic integrated boost. The developed methodologies will result in prospective interventional trials that test the concept of 4D motion corrected MR guided adaptive radiotherapy.

该项目的目的是研究混合1.5T磁共振-直线加速器系统照射期间(组内)和组间(组间)的肿瘤运动。这种混合设备可以通过基于解剖和功能MRI的个性化剂量处方来促进新的和创新的治疗策略的开发。这在肝肿瘤和直肠肿瘤中尤其令人感兴趣，因为周围健康的肝组织通常是剂量有限的，当计划增加剂量以提高完全应答率和促进器官保存时。然而，由于呼吸(肝脏)或直肠和膀胱充盈的变化，这两个肿瘤部位都是移动的靶点。因此，高精度个体化剂量处方的一个先决条件是评估分部内和分部间的肿瘤运动。在这个项目中，我们将为1.5T磁共振直线加速器建立一个优化的四维成像方案，包括解剖和功能成像序列。在此基础上，我们将开发一种4D反应自适应方案，用于肝脏肿瘤的立体定向全身放射治疗(SBRT)。我们的想法是根据发生放射性肝病(RILD)的风险以及组分之间在解剖和功能成像上看到的反应来个体化剂量处方。对于直肠癌，目标是评估整个肿瘤的分割内和分割间的运动，以及可能作为“生物增强”靶点的潜在亚体积。这个BioBoost亚体积是通过在扩散加权成像上观察到的变化来定义的，这已经被证明可以预测肿瘤的消退。在这个项目中，我们将使用通过治疗过程评估的可用的成像数据来进一步完善这些模型，并测试不同的BioBoost策略，如顺序增强或立体定向集成增强。所开发的方法将导致测试4D运动校正MR引导自适应放射治疗的概念的前瞻性介入试验。