Image Guided Integrated Active Breath Hold Radiotherapy

描述(申请人提供)：控制原发肿瘤是癌症放射治疗的主要目标。增加给肿瘤的剂量提供了一种改善局部控制的方法。尤其是肺癌患者，呼吸诱导的器官运动阻碍了安全剂量的增加。补偿这种运动或固定肿瘤的方法是近年来发展起来的。然而，由于缺乏表征呼吸诱导器官运动不确定性的数据，这些新技术并未与降低的边际一起应用，从而使剂量增加。确定与肿瘤固定相关的不确定性，以便能够使用适当的边缘是至关重要的。我们的假设是，图像引导技术和集成的主动屏气放射治疗相结合，将能够表征和减少因呼吸诱导的器官运动而产生的几何不确定性。主动呼吸控制(ABC)已被证明是乳腺癌患者一种安全有效的肿瘤固定方法，它可以减少对正常组织结构(如心脏和肺)的剂量。然而，对于肺癌患者，ABC技术必须进行调整，以提高有肺顺应性问题的患者的依从性。此外，将图像引导技术与ABC放射治疗相结合，能够表征和减少日常设置变化和制动不确定性。本项目的具体目标是(1)测量综合主动屏气放射治疗中肿瘤固定的随机性和系统性不确定性。(2)针对这些不确定性的存在，评估模型图像引导策略，并设计用于补偿这些不确定性的治疗裕度。(3)在一小部分患者中量化剩余设置误差。

DESCRIPTION (provided by applicant): Control of the primary tumor is a major goal of radiotherapy for cancer. Escalating the dose delivered to the tumor provides a method to improve local control. For lung cancer patients in particular, respiratory-induced organ motion has impeded safe dose escalation. Methods to compensate for this motion or to immobilize the tumor have been developed in recent years. However, these new technologies have not been applied in concert with reduced margins that would enable dose escalation due to the lack of data characterizing uncertainty in respiratory-induced organ motion. It is critical to characterize the uncertainties associated with tumor immobilization to enable the use of appropriate margins. It is our hypothesis that the combination of image guidance techniques and integrated active breath hold radiotherapy will enable characterization and reduction of the geometric uncertainties due to respiratory-induced organ motion. Active breathing control (ABC) has been shown to be a safe and effective means of tumor immobilization for breast cancer patients which allows for the reduction of the dose to normal tissue structures such as the heart and lungs. For lung cancer patients, however, the ABC technique must be adapted to increase compliance for patients with pulmonary compliance issues. Furthermore, the integration of image guidance techniques with ABC radiotherapy enables the characterization and reduction of daily setup variation and immobilization uncertainty. The specific aims of this project are to (1) Measure the random and systematic uncertainties of tumor immobilization for integrated active breath hold radiotherapy. (2) Evaluate a model image-guidance strategy with respect to the presence of these uncertainties and to design a treatment margin to compensate for these uncertainties. (3) Quantify residual setup error in a small population of patients.