Quantitative SPECT for dosimetry of 131I molecular radiotherapy

本项目的目的是开发和评估一个定制设计的γ射线成像系统的性能，这将有助于分子放射治疗（MRT）的定量剂量测定。在MRT中，施用放射性示踪剂以将高辐射剂量递送到靶组织，而对周围健康组织的损伤最小。最常用的放射性核素是B放射性同位素131 I，主要用于治疗甲状腺癌。治疗计划目前是不期望的通用的，因为131I是以针对手术固定或根据患者体重缩放的活性来施用的。由于使用诊断成像系统进行治疗成像的局限性，MRT的剂量测定极具挑战性，并且图像量化和空间分辨率可能会出现错误。因此，很难确定治疗的影响。从131 I发射的γ射线可以使用伽马相机成像，然而，常规成像系统的性能不足以进行剂量测定。因此，将使用碲锌镉（CZT）探测器开发一个优化的演示系统。单光子发射计算机断层扫描（SPECT）可用于364 keV 131 I γ射线成像，因此将开发基于CZT探测器和专用集成电路（ASIC）读出的SPECT探测器系统用于治疗成像。该系统旨在制定个性化的癌症治疗计划，从而提高生活质量，降低成本，并对当前的MRT治疗计划政策进行必要的修改。

The aim of this project is to develop and evaluate the performance of a custom-designed y-ray imaging system that will facilitate quantitative dosimetry for Molecular Radiotherapy (MRT). In MRT, radiotracers are administered to deliver high radiation doses to targeted tissue with minimal damage to surrounding healthy tissue. The most common radionuclide used is the B-emitting isotope 131I, predominantly used in the treatment of thyroid cancer. The treatment plans are currently undesirably generic in that 131I is administered with an activity that is either fixed for a procedure or scaled according to patient weight. Dosimetry for MRT is extremely challenging due to limitations that arise from using diagnostic imaging systems for therapeutic imaging, and errors can arise in image quantification and spatial resolution. Therefore, it is difficult to qualify the impact of the treatment. The y-rays emitted from 131I can be imaged using a gamma camera, however, the performance of conventional imaging systems is not sufficient for dosimetry. Consequently, an optimised demonstrator system will be developed using Cadmium Zinc Telluride (CZT) detectors. Single Photon Emission Computed Tomography (SPECT) can be used to image the 364 keV 131I y-rays, therefore a SPECT detector system will be developed for therapeutic imaging based on CZT detectors and Application-Specific Integrated Circuit (ASIC) readout. This system is targeted at personalised cancer treatment plans and in turn will improve quality of life, reduce costs and enable required changes to current MRT treatment planning policies.