Image-Guided Adaptive Radiotherapy

描述（由申请人提供）：本项目的目的是研究图像引导放射治疗技术，通过结合生物成像来改善靶标描绘和实现图像引导适应性放射治疗（IGART）的集成和临床实用系统，从而安全提供更具侵略性的剂量方案。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，显著减少治疗组织体积，同时减少剂量递送到扩大的原发性和局部肿瘤靶点的不确定性。这将使我们能够更精确地针对已知的原发肿瘤和淋巴结转移区域的剂量/分数递增，同时通过正常组织避免减少早期和晚期的后遗症。我们建议首先针对三种患者群体开发IGART：宫颈、前列腺和肺部的局部晚期恶性肿瘤，文献支持通过向原发性和局部疾病靶点增加剂量来改善结果。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中描绘的目标映射到日常治疗CT研究中，并通过IGART治疗过程跟踪组织体素的轨迹。项目2将描述并尽量减少变形解剖体的剂量计算误差；并开发概率IMRT计划工具，以最佳地管理剩余误差。项目3将对宫颈癌和前列腺癌患者进行临床研究，量化患者设置和组织变形的不确定性，优化估计日常解剖的策略，进行适应性重新规划，并将近距离治疗和IMRT纳入IGART过程。项目4将利用临床研究来开发和研究4D IGART系统，以解释准周期性的吸气内呼吸运动变化以及干涉解剖变化。为了支持这些项目，核心A将开发一种新的分层图像管理和软件开发基础设施，以及一个QA范例，用于解决在线IGART带来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.