Image-guided IMRT and Brachytherapy for Pelvic Tumors

局部晚期宫颈癌和中危前列腺癌患者的生存率 受到局部/区域控制欠佳的影响。我们假设通过整合近距离放射治疗 采用高度适形IMRT进行原发性肿瘤治疗，准确地提供剂量/分次递增， 近距离放射治疗未充分治疗的已知原发性和转移性淋巴结疾病区域将允许 减少总治疗时间，增加生物有效剂量， 在目前的技术下是安全的。为了实现这些目标，我们将与项目1和2合作 应用并临床验证可变形图像配准工具，以准确传输信息 从生物成像研究到规划X射线计算机断层摄影（CT）图像（体素标记）， 将近距离放射治疗剂量分布映射到IMRT计划图像上， 基于连续CT成像的患者解剖结构模型（4D体素轨迹）。我们会调查一个家庭 基于4D体素轨迹的图像引导自适应放射治疗（IGART），概率治疗 计划以及离线和在线计划调整，以补偿患者解剖结构的变化。的目的 IGART旨在最大限度地减少因设置误差和内部组织运动引起的几何输送不确定性， 每部分剂量递增可以以最小的边缘施用于靶组织， 最大限度地避开正常组织具体目标1。我们将在两名患者中进行临床研究， 人口和实施和验证量化3D组织变形不确定性的工具， 研究最小化体素标记和近距离放射治疗剂量引起的系统误差的方法 映射. Specific Aim 2将开发从连续CT构建4D体素轨迹的方法 图像并评估其不确定性。评估患者4D解剖结构的最佳方法 将研究每天治疗前的配置。具体目标3将执行模拟虚拟 临床试验，以确定和优化最合适的IGART形式，使临床获益最大化 相对于成本。具体目标4。选择IGART过程的原型用于临床实施 将被开发。将进行临床研究，以确认IGART的可行性和剂量靶向 精度

The survival of patients with locally advanced cervix cancer and intermediate risk prostate cancer is compromised by suboptimal local/regional control. We hypothesize that by integrating brachytherapy primary tumor treatment with highly conformal IMRT that accurately delivers dose-per-fraction escalation to regions of known primary and metastatic nodal disease not adequately treated by brachytherapy will allow overall treatment time to be reduced and biologically effective dose to be increased beyond levels considered safe with current technology. To achieve these goals we will collaborate with Projects 1 and 2 to apply and clinically validate deformable image registration tools for accurately transferring information from biological imaging studies to planning x-ray computed tomography (CT) images (voxel labeling), mapping brachytherapy dose distributions onto IMRT planning images, and constructing 4-dimensional models (4D voxel trajectories) of patient anatomy based upon serial CT imaging. We will investigate a family of image-guided adaptive radiation therapy (IGART) based upon 4D voxel trajectories, probabilistic treatment planning, and off- and on-line plan adaptations to compensate for changes in patient anatomy. The aim of IGART is to minimize geometric delivery uncertainties arising from setup error and internal tissue motion so that dose-per-fraction escalation can be administered to the target tissue with minimum margins and maximum normal tissue avoidance. In Specific Aim 1. we will perform clinical studies in the two patient populations and implement and validate tools for quantifying 3D tissue deformation uncertainties and investigate methods for minimizing systematic errors arising from voxel labeling and brachytherapy dose mapping. Specific Aim 2 will develop approaches for constructing 4D voxel trajectories from serial CT images and assess their uncertainties. Optimal methods for estimating the patient's 4D anatomy configuration prior to each day's treatment will be investigated. Specific Aim 3 will perform simulated virtual clinical trials to identify and optimize the most appropriate form of IGART for maximizing clinical benefit relative to costs. In Specific Aim 4. a prototype of the IGART process selected for clinical implementation will be developed. Clinical studies will be performed to confirm IGART feasibility and dose targeting accuracy.