Optimizing MR-linac motion phantom for treatment plan verification

放射治疗（RT）已经迅速发展到准确和精确地靶向肿瘤，同时保留正常组织。质量控制（QC）测试用于检测可能导致辐射输送错误的过程故障。幻影是一种测试工具，允许医学物理学家表征机器性能并验证放射治疗计划。辐射输送机的最新创新，MR-Linac，需要新的模型和QC方法来适应其日益增加的复杂性。MR-Linac的主要优点之一是出色的软组织对比，更适合自适应RT。对于存在复杂运动的疾病部位，这种自适应RT只能通过4D MRI成像和相关的4D治疗计划方法来实现。该项目的目标是Sunnybrook MR-linac医学物理小组与Modus QA团队合作，优化和商业化MRI4D运动幻影的两个配件。其中一个附件是一个剂量计插入，它有多个光激发发光剂量计（osld），用于测量肿瘤模型周围的剂量分布。第二个配件是一个可变形运动插件，它使用往复活塞压缩泡沫组织/肿瘤模型，以产生复杂的4D变形和滞后。每个原型的详细评估以及QA方法的建议将使用Sunnybrook MR-Linac开发。该项目将通过开发一种MR-Linac运动管理的质量控制流程，使癌症患者的长期临床需求受益。此外，该项目将支持安大略省公司的发展。

Radiation Therapy (RT) has rapidly evolved to accurately and precisely target tumors while sparing normal tissue. Quality control (QC) testing is used to detect process failures which could result in errors in radiation delivery. Phantoms are test tools that allow medical physicists to characterize machine performance and verify radiation therapy plans. The latest innovation in radiation delivery machines, the MR-Linac, requires new phantoms and QC methods tailored to its increased complexity. One of the main advantages of the MR-Linac is the excellent soft tissue contrast, which is better suited for adaptive RT. For disease sites where complex motion is present, this adaptive RT can only be realized with 4D MRI imaging and associated 4D treatment planning methods. The objective of this project is for the Sunnybrook MR-linac medical physics group to partner with the Modus QA team to optimize and commercialize two accessories for the MRI4D motion phantom. One accessory is a dosimetry insert, which has multiple Optically Stimulated Luminescence Dosimeters (OSLDs) for measurement of the dose distribution around a tumour model. The second accessory is a deformable motion insert, which uses reciprocating pistons to compress a foam tissue/tumor model to generate complex 4D deformation and hysteresis. A detailed evaluation of each prototype as well as recommendations on QA methodology will be developed using the Sunnybrook MR-Linac. This project will benefit the long term clinical needs of cancer patients by developing a QC process for MR-Linac motion management. Additionally, this project will support the growth of an Ontario-based company.