Image-Guided Adaptive Radiotherapy

描述（由申请人提供）： 该计划的目的是研究图像引导放射治疗技术，通过生物成像改善靶区勾画和实施图像引导自适应放射治疗（IGART）的综合临床实用系统，实现更积极剂量方案的安全输送。IGART使用每日机载成像，包括3D CT，加上在线3D/4D IMRT自适应重新规划，以大大减少治疗的组织体积，同时减少剂量输送到扩展的主要和区域肿瘤靶点的不确定性。这将使我们能够更精确地将每部分剂量递增仅针对已知具有原发性肿瘤和淋巴结转移的区域，同时通过避免正常组织来减少早期和晚期后遗症。我们建议最初针对三个患者群体开发IGART：宫颈、前列腺和肺的局部晚期恶性肿瘤，其中文献支持通过剂量递增至主要和区域疾病目标来改善结局。在项目1中开发的新型可变形图像配准和重建方法将允许将生物成像研究上描绘的目标映射到日常治疗CT研究上，并通过IGART治疗过程跟踪组织体素的轨迹。项目2将描述并最大限度地减少变形解剖结构的剂量计算误差;并开发概率IMRT计划工具，以最佳地管理残留误差。项目3将对宫颈癌和前列腺癌患者进行临床研究，以量化患者设置和组织变形的不确定性，并优化评估日常解剖结构的策略，进行自适应重新规划，并将近距离放射治疗和IMRT整合到IGART过程中。项目4将利用临床研究开发和研究4D IGART系统，以解释准周期性分次内呼吸运动变化沿着分次间解剖结构变化。为了支持这些项目，核心A将开发一种新型的分层图像管理和软件开发基础设施，以及一种QA范式，用于解决在线IGART造成的独特错误路径和后勤限制，而核心B将提供管理、生物统计和生物建模支持。

DESCRIPTION (provided by applicant): The objective of this Program is to investigate image-guided radiotherapy technology to enable safe delivery of more aggressive dose regimens through a combination of biological imaging for improved target delineation and implementation of an integrated and clinically practical system of image-guided adaptive radiation therapy (IGART). IGART uses daily onboard imaging, including 3D CT, coupled with online 3D/4D IMRT adaptive replanning to dramatically reduce treated tissue volumes while simultaneously reducing the uncertainty of dose delivery to extended primary and regional tumor targets. This will allow us to more precisely target dose-per-fraction escalation only to regions known to harbor primary tumor and nodal metastases while reducing early and late sequelae by normal tissue avoidance. We propose to develop IGART initially for three patient populations: locally advanced malignancies of the cervix, prostate, and lung, where the literature supports improved outcomes by dose escalation to both primary and regional disease targets. Novel deformable image registration and reconstruction methods developed in Project 1 will allow mapping of targets delineated on biological imaging studies onto daily treatment CT studies and tracking of trajectories of tissue voxels through a course of IGART therapy. Project 2 will characterize and minimize dose-calculation errors on deforming anatomies; and develop probabilistic IMRT planning tools for optimally managing residual errors. Project 3 will conduct clinical studies of cervical and prostate cancer patients to quantify patient setup and tissue deformation uncertainties and to optimize strategies for estimating the daily anatomy, performing adaptive replanning, and to integrate brachytherapy and IMRT into the IGART process. Project 4 will utilize clinical studies to develop and investigate a 4D IGART system to account for quasiperiodic intrafraction breathing motion variations along with interfraction anatomic changes. In support of the projects, Core A will develop a novel layered image management and software development infrastructure and a QA paradigm for addressing the unique error pathways and logistical constraints posed by online IGART while Core B will provide administrative, biostatistical, and biomodeling support.