Motion Management of Pancreatic Cancer in MRI-Guided Radiotherapy

MRI 引导放射治疗中胰腺癌的运动管理

• 批准号: 9243999
• 负责人: Ke Sheng
• 金额: $ 33.7万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-03-01 至 2020-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9243999
• 关键词: Abdomen; Algorithms; Anatomy; Breathing; Cancer Patient; Clinical; Data; Development; Diagnosis; Dictionary; Dose; Extravasation; Heterogeneity; Image; Learning; Lung; Lung Neoplasms; Magnetic Resonance Imaging; Malignant Neoplasms; Malignant neoplasm of abdomen; Malignant neoplasm of cervix uteri; Malignant neoplasm of liver; Malignant neoplasm of pancreas; Manuals; Methods; Monitor; Motion; Nature; Operative Surgical Procedures; Organ; Pancreas; Pancreatic Adenocarcinoma; Patients; Pelvic Cancer; Periodicity; Phase; Process; Radiation Tolerance; Radiation therapy; Research; Resectable; Roentgen Rays; Sampling; Speed; Structure of parenchyma of lung; System; Techniques; Testing; Three-Dimensional Image; Time; Variant; X-Ray Computed Tomography; base; cancer radiation therapy; cancer therapy; chemoradiation; clinical imaging; contrast imaging; data space; density; design; dosimetry; effective therapy; improved; improved outcome; innovation; learning strategy; novel; outcome forecast; pancreas visualization; pancreatic neoplasm; prospective; public health relevance; radiosensitive; response; soft tissue; success; tool; treatment planning; tumor

DESCRIPTION (provided by applicant): Significance: Internal organ motion is one of the greatest technical challenges for pancreatic cancer radiation therapy. Extensive research has been conducted on intrafractional tumor motion. This research has provided quantification and enabled novel treatment methods to mitigate motion induced adverse dosimetry effects. Compared to widely studied lung tumor motion, improving pancreas treatment accuracy has equal or greater clinical importance where the tumor is surrounded by radiosensitive serial organs, sparing of which will significantly improve our ability to deliver more effective doses to the tumor. However, organ motion management in the pancreatic cancer treatment is severely underdeveloped due to technical challenges related to poor soft tissue X-ray and CT contrast of pancreas. Fiducial markers are not commonly placed and when placed, inadequately describe complicated multiple-organ motion. Innovation: MRI guided radiotherapy has the potential to overcome these challenges utilizing gated radiotherapy based on organ distances instead of a pre-selected breathing phase. However, to enable it for such pancreatic motion management, MRI acquisition speed needs to be increased so dynamic volumetric images can be acquired with sufficient quality for organ delineation. Furthermore, methods to rapidly digest both pre- and during-treatment MRI images for clinical motion management have not been developed. Both individualized motion margin and gated radiotherapy require explicit organ segmentation but manual delineation of the large number of imaging frames is impractical. Automated segmentation tools for pancreas have not been developed but urgently needed. We will acquire accelerated 3D MRI with sufficient quality for motion quantification by exploiting the spatial and temporal coherence of patient anatomy. We will develop a novel manifold clustering constrained dictionary learning (MCDL) method to efficiently segment the MRI images and provide accurate motion assessment for pancreas anatomy. We hypothesize that the improved motion monitoring will result in significantly improved tumor dose and surrounding normal organ sparing. Aims: 1. Develop methods to acquire 3D dynamic images from under-sampled k-space data. 2. Develop a process to auto-segment prospectively acquired accelerated MRI images by optimizing and validating a MCDL method. 3. Quantify dosimetric gains using accurately described pancreatic tumor motion. Test and robustness and deliverability of the proposed gated plans on a MRI-guided radiotherapy machine (ViewRay). Impact: Patients with locally advanced pancreatic adenocarcinoma have a dismal prognosis but the median survival can be significantly improved for patients who have complete local response. Success of the project will define more accurate patient specific motion margins and facilitate gated radiotherapy that significantly reduce critica organ doses, increase tumor doses for greater complete local response rates. Methods developed by this project will also be applicable to other tumors such as the cervical and liver cancer.

描述（由申请人提供）： 意义：胰腺癌放射治疗的最大技术挑战之一是内部器官运动。已经对分次内肿瘤运动进行了广泛的研究。这项研究提供了量化，使新的治疗方法，以减轻运动引起的不良剂量影响。与广泛研究的肺肿瘤运动相比，提高胰腺治疗精度具有同等或更大的临床重要性，其中肿瘤被放射敏感的系列器官包围，保留这些器官将显著提高我们向肿瘤输送更有效剂量的能力。然而，胰腺癌治疗中的器官运动管理由于与胰腺的软组织X射线和CT对比度差相关的技术挑战而严重不足。基准标记通常不放置，放置时，不能充分描述复杂的多器官运动。创新：MRI引导的放射治疗有可能克服这些挑战，利用基于器官距离的门控放射治疗，而不是预先选择的呼吸阶段。然而，为了使其能够用于这样的胰腺运动管理，需要增加MRI采集速度，以便能够以足够的质量采集动态体积图像用于器官描绘。此外，还没有开发出用于临床运动管理的快速消化治疗前和治疗期间MRI图像的方法。个体化运动裕度和门控放射治疗都需要明确的器官分割，但手动描绘大量的成像帧是不切实际的。胰腺的自动分割工具尚未开发，但迫切需要。我们将通过利用患者解剖结构的空间和时间相干性来获得具有足够质量的加速3D MRI以进行运动量化。我们将开发一种新的流形聚类约束字典学习（MCDL）方法，有效地分割MRI图像，并提供准确的胰腺解剖运动评估。我们假设改进的运动监测将导致显著改善的肿瘤剂量和周围正常器官的保留。目的：1.开发从欠采样k空间数据获取3D动态图像的方法。2.通过优化和验证MCDL方法，开发自动分割前瞻性采集的加速MRI图像的过程。3.使用准确描述的胰腺肿瘤运动量化剂量增益。在MRI引导放射治疗机（ViewRay）上测试拟定门控计划的稳健性和可输送性。影响：局部晚期胰腺癌患者预后差，但局部完全缓解患者的中位生存期可显著提高。该项目的成功将定义更准确的患者特定运动裕度，并促进门控放射治疗，显著降低关键器官剂量，增加肿瘤剂量，以获得更高的完全局部缓解率。该项目开发的方法也将适用于其他肿瘤，如宫颈癌和肝癌。