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存活率为 受到次优的本地/区域控制的影响。我们假设通过整合近距离放射治疗 采用高度适形调强放射治疗的初级肿瘤治疗，可准确地将每分次剂量递增到 未经近距离放射治疗充分治疗的已知原发和转移性结节病变区域将允许 总体治疗时间缩短，生物有效剂量增加超过水平 在目前的技术下被认为是安全的。为了实现这些目标，我们将与项目1和项目2合作 用于准确传递信息的可变形图像配准工具的应用和临床验证 从生物成像研究到计划X射线计算机断层扫描(CT)图像(体素标记)， 将近距离照射剂量分布映射到调强放射治疗计划图像上，并构建4维 基于连续CT成像的患者解剖模型(4D体素轨迹)。我们将调查一个家庭 基于4D体素轨迹的图像引导自适应放射治疗(IGART)的概率治疗 计划、离线和在线计划调整，以补偿患者解剖结构的变化。的目的是 IGART旨在将由安装误差和内部组织运动引起的几何交付不确定性降至最低 这种每部分剂量的递增可以以最小的边际给药到目标组织并且 最大限度地避免正常组织。具体目标1.我们将对这两名患者进行临床研究。 填充并实施和验证用于量化3D组织变形不确定性和 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。特定目标2将开发从序列CT构建4D体素轨迹的方法 并评估其不确定度。估计患者4D解剖结构的最佳方法 将对每天治疗前的配置进行调查。《特定目标3》将执行模拟虚拟 确定和优化最合适的IGART形式以实现临床效益最大化的临床试验 相对于成本。具体目标4.选定用于临床实施的IGART过程的原型 将会被开发出来。将进行临床研究以确认IGART的可行性和剂量靶向 精确度。

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.