Development of a high quantum efficiency and tissue equivalent flat-panel X-ray detector for radiotherapy applications

“癌症问题”是加拿大最严重的健康问题。大约一半的癌症患者接受放射治疗。这类治疗的几何和剂量精度是其成功的关键。目前，几何验证(即在治疗过程中肿瘤或靶点位于预期位置的验证)和剂量验证(即向靶点提供的规定辐射剂量的验证)是使用两个尚未完全优化的不同系统来完成的，并且没有单一的工具可以在治疗期间同时进行几何和剂量验证。在这项应用中，我们建议开发一种新的系统，既能验证靶点位置，又能验证患者体内的剂量。这个系统(这类系统中的第一个)被设计成在检测X射线方面非常有效(高的“量子效率”)，并且在成分上与人体组织(“组织当量”)相似，它的优点是允许我们测量辐射剂量，就像它在患者体内传递的那样。我们的新系统不仅更简单，而且比目前的几何和剂量学验证系统具有更好的准确性。它是基于一种新的概念，即使用塑料闪烁纤维进行兆伏X射线成像。这项研究预计将在三个主要方面造福加拿大人：(1)通过扩大我们对闪烁光及其在医学上的应用的知识，(2)通过为放射治疗提供一种新的、更简单和更准确的成像和剂量测量工具，以确保以最小的风险获得最佳的患者结果，以及(3)通过培训卫生保健行业所需的高素质人员。

The "cancer problem" is the most significant health problem in Canada. Approximately half of cancer patients receive radiation therapy treatments. The geometric and dosimetric accuracies of such treatments are crucial for their success. Currently, the geometric verification (i.e., verification of the tumor or target being positioned at the intended location during the treatment) and dosimetric verification (i.e., verification of the prescribed radiation dose being delivered to the target) are accomplished using two different systems that are not yet fully optimized, and there is no single tool available that can be used to do both geometric and dosimetric verification during the treatment. In this application, we propose to develop a novel system capable of both verifying target position, as well as verifying the dose delivered within the patient. This system (the first of this kind), is designed to be both very efficient at detecting X rays (high "quantum efficiency") and similar in composition to human tissue ("tissue equivalent"), which has the advantage of allowing us to measure radiation dose as it would be delivered within a patient. Our new system will not only be simpler but also have a better accuracy than the current systems for geometric and dosimetric verification. It is based on a new concept of using plastic scintillation fibres for megavoltage X-ray imaging. The research is expected to benefit Canadians in three major ways: (1) by expanding our knowledge of scintillation light and its application in medicine, (2) by providing a new, simpler and more accurate imaging and dosimetric tool for radiation therapy treatments to ensure the best patient outcome with the least risk, and (3) by training highly qualified personnel needed in the health care industry.