文章：

基于锥形束计算机断层扫描的合成计算机断层扫描在笔形束扫描质子治疗适应性评估中的应用与陷阱

The Applications and Pitfalls of Cone-Beam Computed Tomography-Based Synthetic Computed Tomography for Adaptive Evaluation in Pencil-Beam Scanning Proton Therapy

原文发布日期：22 October 2023

DOI: 10.3390/cancers15205101

类型: Article

开放获取: 是

英文摘要：

Purpose: The study evaluates the efficacy of cone-beam computed tomography (CBCT)-based synthetic CTs (sCT) as a potential alternative to verification CT (vCT) for enhanced treatment monitoring and early adaptation in proton therapy. Methods: Seven common treatment sites were studied. Two sets of sCT per case were generated: direct-deformed (DD) sCT and image-correction (IC) sCT. The image qualities and dosimetric impact of the sCT were compared to the same-day vCT. Results: The sCT agreed with vCT in regions of homogeneous tissues such as the brain and breast; however, notable discrepancies were observed in the thorax and abdomen. The sCT outliers existed for DD sCT when there was an anatomy change and for IC sCT in low-density regions. The target coverage exhibited less than a 5% variance in most DD and IC sCT cases when compared to vCT. The Dmaxof serial organ-at-risk (OAR) in sCT plans shows greater deviation from vCT than small-volume dose metrics (D0.1cc). The parallel OAR volumetric and mean doses remained consistent, with average deviations below 1.5%. Conclusion: The use of sCT enables precise treatment and prompt early adaptation for proton therapy. The quality assurance of sCT is mandatory in the early stage of clinical implementation.

摘要翻译： 

目的：本研究评估基于锥形束计算机断层扫描（CBCT）的合成CT（sCT）作为验证CT（vCT）潜在替代方案的效能，以增强质子治疗中的治疗监测与早期适应性调整。方法：研究涵盖七个常见治疗部位。每例生成两组sCT：直接形变（DD）sCT与图像校正（IC）sCT。将sCT的图像质量与剂量学影响与同日获取的vCT进行对比分析。结果：在脑部、乳房等均匀组织区域，sCT与vCT表现一致；但在胸腹部观察到显著差异。当存在解剖结构变化时，DD sCT会出现异常值；而IC sCT在低密度区域存在偏差。与vCT相比，多数DD与IC sCT病例的靶区覆盖差异小于5%。sCT计划中串联型危及器官（OAR）的Dmax指标较vCT的偏差大于小体积剂量指标（D0.1cc）。并联型OAR的体积剂量与平均剂量保持稳定，平均偏差低于1.5%。结论：sCT的应用可实现质子治疗的精准实施与及时早期调整。在临床推广初期必须建立严格的sCT质量保证体系。

原文链接：

The Applications and Pitfalls of Cone-Beam Computed Tomography-Based Synthetic Computed Tomography for Adaptive Evaluation in Pencil-Beam Scanning Proton Therapy