Developing an Accurate and Reliable Method for Tumor Motion Monitoring for Tumor

该项目旨在开发一种创新的物理方法，以准确预测在立体定向放射治疗（SBRT）过程中移动的肺肿瘤的位置。该策略涉及使用四维计算机断层扫描（4DCT）在模拟时校准肿瘤基础模型，并使用基于视频的光学表面成像（4DSI）提供运动适应以推断治疗期间的肿瘤位置。该肿瘤运动模型考虑了呼吸不规则性和基线漂移，这不能由任何现有的基于相关性的运动替代来处理。因此，所提出的方法潜在地提供了用于运动跟踪SBRT的监测移动肿瘤的准确、可靠和非放射性手段。在此之前，李博士发现了躯干容积变化与动态潮气量和平均膈肌运动的物理关系。他与魏博士合作了1.5年，并发表了2篇关于肺运动特征和呼吸周期的论文，这得益于魏博士在计算机视觉和机器学习方面的专业知识。初步数据已经生成，包括4DSI在体积测量中的准确性评估、肿瘤运动扰动模型的框架以及肺通气和运动的表征。因此，我们假设这种基于物理定律的方法将提供肿瘤位置的准确估计，从而可能改善癌症的放射治疗。特别是，我们建议建立一个肿瘤运动扰动模型，同时使用4DCT和4DSI。我们将描述移动肿瘤与支气管树、胸壁、横膈膜和躯干表面之间的物理关系（见具体目标1）。我们将建立一个运动基础模型，将4DSI应用于空间和时间输入，并最终确定运动扰动模型。我们还建议通过志愿者和患者研究建立基于4DSI的肺功能测定法并临床验证所提出的方法（见具体目标2）。我们将为患者研究建立IRB方案，同时使用4DSI和荧光透视来验证肿瘤运动模型。我们还将使用4DMR和肺量测定法研究志愿者的呼吸。该试点项目将证明这种新方法可以在4D图像引导SBRT中准确靶向肺部肿瘤的原理。

This project aims to develop an innovative physical approach to accurately predict the location of a moving lung tumor during streotactic body radiotherapy (SBRT). The strategy involves using four-dimensional computed tomography (4DCT) to calibrate a tumor base-model at simulation and using video-based optical surface imaging (4DSI) to provide motion adaptation to infer tumor position during treatment. This tumor motion model accounts for breathing irregularities and baseline drift, which cannot be handled by any existing correlation-based motion surrogate. Therefore, the proposed method potentially provides an accurate, reliable, and non-radiological means of monitoring a moving tumor for motion-tracking SBRT. Previously, Dr. Li discovered the physical relationships of torso-volume change with dynamic tidal volume and mean diaphragm motion. He has collaborated with Dr. Wei for 1.5 years and published 2 papers on lung motion characterization and breathing periodicity, facilitated by Dr. Wei's expertise in computer vision and machine learning. Preliminary data have been generated, including accuracy assessment of 4DSI in volume measurement, framework for a tumor motion perturbation model, and characterization of lung ventilation and motion. We therefore hypothesize that this physical law-based method will provide an accurate estimation of tumor location, thereby potentially improving radiation therapy for cancer. In particular, we propose to establish a tumor motion perturbation model using both 4DCT and 4DSI. We will characterize the physical relationship between a moving tumor and the bronchial tree, chest wall, diaphragm, and torso surface (see Specific Aim 1). We will build a motion base model, apply 4DSI for spatial and temporal inputs, and finalize the motion perturbation model. We also propose to establish 4DSI-based spirometry and clinically validate the proposed method, through both volunteer and patient studies (see Specific Aim 2). We will establish an IRB protocol for patient studies using concurrent 4DSI and fluoroscopy to validate the tumor motion model. We will also study volunteer respiration using 4DMR and spirometry. This pilot project will demonstrate the proof of principle that this novel approach can accurately target lung tumors in 4D image-guided SBRT.