Respiratory Motion-Reduced Cone-Beam CT Guidance of Radiotherapy in Lung & Liver

呼吸运动减少锥束CT指导肺部放射治疗

• 批准号: 7802162
• 负责人: GIKAS S MAGERAS
• 金额: $ 53.55万
• 依托单位: SLOAN-KETTERING INST CAN RESEARCH
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-01 至 2013-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7802162
• 关键词: 3-Dimensional; Affect; Anatomic Models; Anatomy; Breathing; Cells; Clinical; Clinical assessments; Complex; Data Set; Dimensions; Discrimination; Disorder by Site; Dose; Effectiveness; Enhancing Lesion; Evaluation; Goals; Image; Implant; Injection of therapeutic agent; Intravenous; Lesion; Linear Accelerator Radiotherapy Systems; Liver; Lung; Malignant neoplasm of lung; Manuals; Medical; Metastatic Lesion; Metastatic Neoplasm to the Liver; Methods; Modeling; Morphologic artifacts; Motion; Noise; Non-Small-Cell Lung Carcinoma; Organ; Patients; Phase; Positioning Attribute; Principal Component Analysis; Procedures; Protocols documentation; Radiation; Radiation therapy; Relative (related person); Reproducibility; Research Project Grants; Respiration; Respiratory Diaphragm; Risk; Scanning; Signal Transduction; Sorting - Cell Movement; System; Techniques; Testing; Therapeutic; Time; Validation; arm; base; clinical efficacy; cone-beam computed tomography; image registration; improved; interest; lung Carcinoma; public health relevance; respiratory; simulation; soft tissue; tumor

DESCRIPTION (provided by applicant): The overall goal of this research project is to improve the accuracy and reliability of cone-beam computed tomography (CBCT) guidance of radiation treatment in lung and liver. The treatment of inoperable tumors in lung and liver remains a therapeutic challenge. Increasing the radiation dose improves local control but requires high-precision techniques. There is widespread interest in linear accelerator-mounted CBCT systems for guiding radiation treatment, but respiratory motion adversely affects CBCT image quality and limits its accuracy. We propose to develop and evaluate methods to reduce respiratory-induced motion artifacts in CBCT. Our hypotheses are: 1) motion-reduction techniques will improve tumor and organ-at-risk (OAR) visibility and localization accuracy in lung and liver, relative to current CBCT methods; 2) motion-reduced CBCT will enable the use of contrast enhancement for localizing liver metastases at treatment, as an alternative to implanted fiducials; and 3) the improved localization accuracy will permit smaller treatment volumes, thereby enabling safe delivery of higher radiation doses. Our specific aims are to 1) develop and validate a model of respiration-induced motion adapted to each patient from respiration-correlated CT and CBCT images; 2) develop a method to reduce motion artifacts in CBCT using the patient-specific motion model; and 3) evaluate motion- reduced CBCT in patients treated with radiation for nonsmall cell lung cancer or liver metastases. The patient-specific motion model uses nonrigid image registration between CT or CBCT images at different respiratory motion states to generate 3D trajectories of all voxels in the volume images. An important component of the model is a principal component analysis that reduces the high-dimensional complex data set to a lower dimension by removing noise and redundancy. The motion reduction procedure sorts the CBCT projections into motion states according to the respiratory signal, reconstructs and morphs the volume image at each motion state to a reference image by means of the patient's motion model, then combines the morphed images to produce a high quality CBCT image. Evaluation of the accuracy of the proposed methods will use physical and analytical deformable phantoms, and manual delineations of clinical images. The first phase of patient studies will compare the ability to visualize and localize tumor and OAR before and after model-based motion reduction improvements to CBCT image quality, using gated CBCT as a reference. The imaging study in liver will test the feasibility of detecting metastatic lesions using motion-reduced CBCT in combination with intravenous contrast injection. The second phase of studies will use motion-reduced CBCT to correct patient position prior to hypofractionated radiotherapy in lung, and determine the fraction of patients for whom higher prescribed dose is achieved through margin reduction made possible by the improved localization accuracy. PUBLIC HEALTH RELEVANCE: There is widespread interest in medical accelerator-mounted cone-beam computed tomography (CBCT) systems for improving the accuracy of radiation treatment; however, breathing motion can blur the images and limit our ability to locate and target tumors in lung and liver. We propose to develop methods to reduce blur and distortion in CBCT images caused by breathing motion. The effectiveness of these methods will be evaluated in patients receiving radiation treatment for lung cancer or liver metastases.

描述（由申请人提供）：该研究项目的总体目标是提高肺和肝脏辐射治疗指导的锥束计算机断层扫描（CBCT）的准确性和可靠性。肺和肝脏中无法手术的肿瘤的治疗仍然是治疗挑战。增加辐射剂量可改善局部控制，但需要高精度技术。对于指导辐射处理的线性加速器系统的CBCT系统引起了广泛的兴趣，但呼吸运动对CBCT的图像质量有不利影响，并限制了其准确性。我们建议开发和评估减少CBCT中呼吸诱导的运动伪像的方法。我们的假设是：1）相对于当前的CBCT方法，运动还原技术将改善肺和肝脏中的肿瘤和器官风险（OAR）的可见性和定位精度； 2）减少运动的CBCT将使对比度增强在治疗中定位肝转移，以替代植入的基金会。 3）提高的定位精度将允许较小的治疗量，从而可以安全地提供更高的辐射剂量。我们的具体目的是1）开发和验证呼吸诱导的运动模型，该运动适用于每个患者的呼吸相关CT和CBCT图像； 2）开发一种使用患者特异性运动模型减少CBCT中运动伪像的方法； 3）评估接受非小细胞肺癌或肝转移辐射治疗的患者的CBCT降低。特定于患者的运动模型在不同呼吸运动状态下使用CT或CBCT图像之间的非素数图像注册来生成体积图像中所有体素的3D轨迹。该模型的重要组成部分是主成分分析，该分析通过消除噪声和冗余，将高维复杂数据集降低到较低的维度。运动还原过程将CBCT投影按照呼吸信号，通过患者的运动模型的方式重建和将每个运动状态的体积图像重建为参考图像，然后将变形图像结合起来以产生高质量的CBCT图像。评估所提出方法的准确性将使用物理和分析可变形的幻象，以及对临床图像的手动描述。患者研究的第一阶段将比较使用门盖式CBCT作为参考，在基于模型的运动减少对CBCT图像质量的改进之前和之后可视化和定位肿瘤和桨的能力。肝脏中的成像研究将测试使用静脉造影剂注射的运动还原CBCT检测转移性病变的可行性。第二阶段的研究将使用运动减少的CBCT在肺中进行降低放疗之前纠正患者位置，并确定通过提高的定位精度可通过降低余量来实现较高处方剂量的患者的比例。公共卫生相关性：对医疗加速器安装式锥束计算机断层扫描（CBCT）系统具有广泛的兴趣，以提高辐射治疗的准确性；但是，呼吸运动可以模糊图像并限制我们在肺和肝脏中定位和靶向肿瘤的能力。我们建议开发方法，以减少由呼吸运动引起的CBCT图像中的模糊和失真。这些方法的有效性将在接受肺癌或肝转移放射治疗的患者中评估。