Real-time in Vivo Dosimetry in Radiation Therapy Using Scintillation Detectors

描述(由申请人提供)：将正确的剂量提供给预期的区域是任何放射治疗的最基本目标。确认向感兴趣地点提供的真实剂量的最直接方法是在现场测量该剂量。在前列腺放射治疗中，结果(生化和局部控制)取决于按计划将剂量准确地输送到前列腺。同时，重要的是确保对关键结构(直肠、尿路和勃起组织)的耐受性在可接受的范围内，以便将毒性降至最低，并不影响生活质量。我们假设，基于剂量的适应性放射治疗可以通过测量传递到器官、关键结构和肿瘤附近的剂量来实现。我们相信，这可以使用体内闪烁探测器来完成，该探测器由多个探测器组成，以特定用途的设计排列，可以实时监测真实的体内剂量。塑料闪烁探测器由三个主要组件组成：在照射时发光(发出可见光)的微型闪烁材料，携带光的光导，以及将光转换为可测量信号的光电探测器。我们将使用直径亚毫米的闪烁纤维，以提高其空间分辨率和灵活性，使其符合内部解剖学的曲率。为了实现这一目标，我们的目标是：a)建立光子和质子放射治疗束中闪烁纤维的剂量学特征和性质；b)设计、建造和测试用于直肠和尿路活体应用的探测器系统；以及c)测量一小部分患者直肠壁和尿路的剂量。该项目的成功完成将产生一种监测放射治疗期间向器官和其他有风险的组织提供的真实剂量的方法。这种方法可以用来产生数据，以评估器官和关键结构的剂量，并改变治疗计划，以最大限度地增加对肿瘤的剂量和/或最大限度地减少对正常组织的并发症风险。由此得到的数据也可以用于研究与剂量相关的治疗副作用。使用这种方法的最终目的是改善放射治疗的提供和放射治疗患者的生活质量。

DESCRIPTION (provided by applicant): Delivering the correct dose to the intended area is the most basic goal of any radiotherapy treatment. The most direct way to confirm the true dose delivered to a location of interest is to measure that dose in situ. In prostate radiotherapy, the outcome (biochemical and local control) depends on accurate delivery of the dose to the prostate as planned. At the same time, it is important to ensure that the tolerance to critical structures (rectum, urethra, and erectile tissues) is within acceptable limits so that toxicity is minimized and quality of life is not compromised. We hypothesize that dose-based adaptive radiotherapy is achievable by measuring the dose delivered to organs, critical structures, and within the vicinity of the tumor. We believe this can be done using an in vivo scintillation detector composed of multiple probes arranged in an application-specific design that can monitor true in vivo dose in real time. Plastic scintillation detectors are constructed from three main components: a miniature scintillating material that luminesces (emits visible light) when irradiated, an optical guide that carries the light, and a photodetector that converts the light into a measurable signal. We will use sub-millimeter diameter scintillating fibers for their spatial resolution as well as their flexibility, allowing them to conform to the curvatures of internal anatomy. In order to reach this goal, we aim to: a) establish the dosimetric characteristics and properties of scintillating fibers in photon and proton radiotherapy beams, b) design, construct, and test detector systems for rectal and urethral in vivo applications, and c) measure the dose to the rectal wall and urethra for a small cohort of patients. Successful completion of this project will result in a method for monitoring the true dose delivered to organs and other tissues at risk during radiotherapy. This method can be used to generate data to assess the dose to the organs and critical structures and alter the treatment plan to maximize the dose to the tumor and/or minimize the risk of complications to normal tissue. The resulting data can also be used to study dose- related treatment side effects. The ultimate goal of utilizing this method is to improve the delivery of radiotherapy treatments and the quality of life of radiotherapy patients.