Image-Guided Adaptive Radiotherapy

描述(申请人提供)：本计划的目标是研究图像引导放射治疗技术，通过结合生物成像改善靶区描绘和实施集成的临床实用的图像引导自适应放射治疗系统(IGART)，安全地提供更具侵袭性的剂量方案。IGART使用包括3D CT在内的每日车载成像，结合在线3D/4D IMRT自适应重新规划，大幅减少治疗组织体积，同时降低向扩大的原发和区域肿瘤靶点提供剂量的不确定性。这将使我们能够更准确地针对仅在已知存在原发肿瘤和淋巴结转移的区域的每分次剂量递增，同时通过正常的组织回避减少早期和晚期后遗症。我们建议IGART最初针对三种患者群体：局部晚期宫颈癌、前列腺癌和肺部恶性肿瘤，文献支持通过将剂量增加到原发和局部疾病目标来改善预后。在项目1中开发的新的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研究上，并通过IGART治疗过程跟踪组织体素的轨迹。项目2将描述和减少变形解剖上的剂量计算误差；并开发概率调强放射治疗计划工具，以最佳地管理残余误差。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，优化评估日常解剖的策略，执行适应性重新计划，并将近距离放射治疗和调强放射治疗整合到IGART过程中。项目4将利用临床研究来开发和研究4D IGART系统，以解释伴随着节间解剖变化的准周期性节段内呼吸运动变化。为支持这些项目，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，以及用于解决在线IGART带来的独特错误路径和后勤限制的质量保证范例，而核心B将提供行政、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.