Markerless Motion Tracking of Lung Tumors using Dual Energy Imaging

使用双能成像对肺部肿瘤进行无标记运动跟踪

• 批准号: 10571893
• 负责人: Mathias Lehmann
• 金额: $ 29.42万
• 依托单位: LOYOLA UNIVERSITY CHICAGO
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-03-15 至 2026-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10571893
• 关键词: 3-Dimensional; Address; Anatomy; Area; Bone Tissue; Chronic Obstructive Pulmonary Disease; Clinical; Communities; Compensation; Development; Devices; Discrimination; Disease Management; Dose; Electromagnetics; Engineering; Ensure; Environment; Excision; Fluoroscopy; Funding; Goals; Grant; Hemorrhage; Image; Incidence; Individual; Institution; Length; Linear Accelerator Radiotherapy Systems; Liver; Lung; Lung Neoplasms; Lung Volume Reductions; Malignant Neoplasms; Malignant neoplasm of lung; Methods; Modality; Motion; Normal tissue morphology; Operative Surgical Procedures; Patients; Pneumothorax; Positioning Attribute; Protocols documentation; Radiation Pneumonitis; Radiation therapy; Research; Research Personnel; Respiration; Risk; Risk Reduction; Roentgen Rays; Sum; System; Techniques; Technology; Testing; Therapeutic; Time; Tissues; Validation; Visualization; X-Ray Medical Imaging; bone; cancer imaging; chemotherapy; clinical development; clinical implementation; clinical practice; cohort; comorbidity; cone-beam computed tomography; contrast imaging; cost effective; digital; feasibility testing; image guided; imager; imaging capabilities; imaging modality; imaging study; implantation; improved; industry partner; innovation; irradiation; logarithm; lung imaging; lung volume; manufacturing capabilities; programs; public health relevance; quality assurance; radiation delivery; radiation risk; radiological imaging; reconstruction; respiratory; soft tissue; success; technology validation; tomosynthesis; tool; tumor

Project Summary/Abstract Lung cancer is one of the most common and deadliest malignancies in the world. Radiation therapy (RT) is often used alone or in combination with surgery or chemotherapy, and thus is a critical component in the management of this disease. However, accurate delivery of RT in the lung is limited by respiratory motion, which can result in significant displacements of the tumor (up to 2 cm). Without compensation, this motion necessitates the irradiation of a larger volume of normal lung to account for displacement of the tumor. This larger volume of lung irradiated increases the incidence of symptomatic radiation pneumonitis. A number of methods have been used clinically to reduce the volume of lung irradiated including the use of breath hold and compression. However, both are uncomfortable and difficult for patients who often have multiple comorbidities. Alternatively, researchers are evaluating methods to track the tumor in real time and potentially adapt the treatment parameters to the position of the lung tumor. Methods to accomplish this goal require the implantation of fiducial markers or electromagnetic transponders. However, implantation of these devices carries a significant risk of pneumothorax, pulmonary hemorrhage and exacerbation of underlying chronic obstructive pulmonary disease (COPD). Another approach for tumor tracking – markerless tumor tracking (MTT) – relies on images of the tumor obtained at the time of treatment. The most common modality for the delivery of RT is the linear accelerator equipped with an on-board imager (OBI). X-ray-based MTT, using planar MV or kV imaging on a standard linear accelerator, is attractive as it uses a widely available technology and can be performed in near real time. In cases where the tumor is clearly visible, x-ray-based MTT can track tumors with a high degree of accuracy. However, a major difficulty with MTT is that tumor-overlapping bone may not be detectable on x-ray projections. Our group has explored dual energy (DE) fluoroscopic imaging to increase the likelihood of successful and accurate MTT, and have implemented DE imaging on the OBI of a commercial linear accelerator using fast-kV switching technology. DE imaging involves obtaining x-ray images at high (i.e., 120 kVp) and low (i.e., 60 kVp) energies. By performing a weighted-logarithmic subtraction (WLS), a third image is produced that suppresses bone and enhances soft tissue/tumor visibility. Our hypothesis is that implementing DE imaging on a linear accelerator will enable a practical and cost effective method for enhanced tumor visualization and image guidance in lung RT. Moreover, DE imaging will allow for MTT ensuring a high dose is delivered to the tumor while limiting the volume of normal tissue irradiated. To test this hypothesis and to accomplish the goals of this research, the following specific aims are proposed: A) Identify areas for improvement in fast-kV DE imaging and MTT with the goal toward clinical implementation and B) Development of a quality assurance program and clinical validation.

项目摘要/摘要 肺癌是世界上最常见和最致命的恶性肿瘤之一。放射治疗(RT) 通常单独使用或与手术或化疗一起使用，因此是 这种疾病的管理。然而，RT在肺内的准确传递受到呼吸运动的限制，这 可导致肿瘤的显著移位(最高可达2厘米)。在没有赔偿的情况下，这项动议必须 照射较大体积的正常肺以说明肿瘤移位。这一更大的体积 肺部照射会增加症状性放射性肺炎的发生率。已经有许多方法被采用 临床上用于减少受照射的肺的体积，包括屏气和按压。 然而，对于经常合并多种疾病的患者来说，这两者都是不舒服和困难的。或者， 研究人员正在评估实时跟踪肿瘤的方法，并可能调整治疗参数 到肺部肿瘤的位置。实现这一目标的方法需要植入基准标记或 电磁应答器。然而，植入这些装置有很大的气胸风险， 肺出血和潜在的慢性阻塞性肺疾病(COPD)的恶化。另一个 肿瘤跟踪的方法--无标记肿瘤跟踪(MTT)--依赖于在 治疗时间。最常见的提供RT的方式是配备有 车载成像仪(OBI)。在标准直线加速器上使用平面mV或kV成像的基于X射线的MTT法是 因为它使用了广泛可用的技术，并且可以近乎实时地执行，所以很有吸引力。在以下情况下 肿瘤清晰可见，基于x射线的四甲基偶氮唑盐可以很高的准确度跟踪肿瘤。然而，一个主要的 MTT法的困难在于，在X光投影上可能无法发现肿瘤重叠的骨。 我们小组探索了双能(DE)荧光成像技术，以增加成功和 并在某商用直线加速器的OBI上用FAST-KV实现了DE成像 交换技术。DE成像包括在高(即120kVp)和低(即60kVp)下获得x射线图像 能量。通过执行加权对数减法(WLS)，产生抑制 骨骼和增强软组织/肿瘤的可见性。我们的假设是在一条直线上实现DE成像 加速器将为增强肿瘤可视化和图像提供一种实用且经济高效的方法 肺放射治疗的指导。此外，DE成像将允许MTT确保高剂量被输送到肿瘤 同时限制照射的正常组织的体积。为了检验这一假设并实现这一目标 通过研究，提出了以下具体目标：a)确定快速千伏DE成像需要改进的领域； 以临床实施为目标的MTT和B)开发质量保证计划和临床 验证。