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。这种治疗的几何和剂量准确性对其成功至关重要。目前，几何验证（即，验证肿瘤或目标在治疗期间定位在预期位置）和剂量测定验证（即，对被递送到目标的规定辐射剂量的验证）是使用尚未完全优化的两个不同系统来完成的，并且没有可用于在治疗期间进行几何和剂量测定验证的单一工具。 在该应用中，我们提出开发一种能够验证靶位置以及验证患者体内输送的剂量的新型系统。该系统（此类系统中的第一个）被设计为在检测X射线（高“量子效率”）方面非常有效，并且在组成上与人体组织（“组织等效物”）相似，这具有允许我们测量辐射剂量的优点，因为它将在患者体内传递。我们的新系统将不仅是简单的，但也有一个更好的准确性比目前的系统的几何和剂量验证。它基于使用塑料闪烁纤维进行兆伏级X射线成像的新概念。该研究预计将在三个主要方面使加拿大人受益：（1）通过扩大我们对闪烁光及其在医学中的应用的知识，（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定工具，以确保以最小的风险获得最佳的患者结果，以及（3）通过培训医疗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.