GenesisCare, Wembley, WA, Australia.
School of Physics, Mathematics and Computing, University of Western Australia, Crawley, Australia.
Phys Eng Sci Med. 2023 Jun;46(2):633-643. doi: 10.1007/s13246-023-01238-3. Epub 2023 Mar 27.
The use of surface guided imaging in cranial stereotactic radiotherapy provides a non-ionising form of patient position verification that gives information on when patient position errors may require corrections to be applied. This work assessed the accuracy of Catalyst HD system for treatment geometries commonly used in cranial SRS. Average Catalyst reported error as a function of couch rotation agreed with measured kV and MV walkout within 0.5 mm for the lateral and longitudinal directions. Change in Catalyst reported error with isocentre depth relative to the monitoring region of interest (ROI) from the surface was assessed and showed variation above 0.5 mm, but within 1 mm for isocentre depths ranging from 3 to 15 cm from the phantom surface. Gantry occlusion of Catalyst cameras caused a shift in reported position error that was also dependent on isocentre depth relative to the monitoring ROI. SRS MapCHECK patients specific QA results showed improvement in gamma passing rates for a workflow where Catalyst reported errors above 0.5 mm were corrected.
表面引导成像在颅部立体定向放射治疗中的应用提供了一种非电离形式的患者位置验证，可提供有关患者位置误差何时需要进行校正的信息。本研究评估了 Catalyst HD 系统在颅部 SRS 中常用治疗几何形状中的准确性。Catalyst 报告的平均误差与侧向和纵向的测量千伏和兆伏外扩值在 0.5 毫米以内一致。评估了相对于监测感兴趣区域（ROI）的等中心深度相对于表面的 Catalyst 报告误差的变化，结果表明在 0.5 毫米以上存在变化，但在 1 毫米以内，等中心深度范围从 3 厘米到 15 厘米。Catalyst 相机的龙门遮挡会导致报告位置误差发生偏移，该偏移也取决于相对于监测 ROI 的等中心深度。SRS MapCHECK 患者特定的 QA 结果表明，在 Catalyst 报告误差超过 0.5 毫米的情况下进行校正的工作流程中，伽马通过率有所提高。
