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。此类治疗的几何和剂量精度对其成功至关重要。目前，几何验证（即验证治疗期间肿瘤或靶标位于预定位置的验证）和剂量验证（即验证向目标输送的规定辐射剂量）是使用尚未完全优化的两个不同系统完成的，并且没有可用的单一工具可用于在治疗期间进行几何验证和剂量验证。 在此应用中，我们建议开发一种新颖的系统，既能够验证目标位置，又能验证患者体内输送的剂量。该系统（此类系统中的第一个）被设计为能够非常有效地检测 X 射线（高“量子效率”），并且其成分与人体组织相似（“组织当量”），其优点是使我们能够测量患者体内传递的辐射剂量。我们的新系统不仅比现有的几何和剂量验证系统更简单，而且具有更高的精度。它基于使用塑料闪烁纤维进行兆伏 X 射线成像的新概念。该研究预计将通过三个主要方式使加拿大人受益：（1）扩展我们对闪烁光及其在医学中的应用的了解，（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.