Department of Oncology, Vejle Hospital, University Hospital of Southern Denmark, Beriderbakken 4, Vejle, DK-7100, Denmark; Radiotherapy Research Team, Vejle Hospital, University Hospital of Southern Denmark, Beriderbakken 4, Vejle, DK-7100, Denmark.
RaySearch Laboratories, Stockholm, SE-103 65, Sweden.
Phys Med. 2022 Nov;103:157-165. doi: 10.1016/j.ejmp.2022.10.012. Epub 2022 Oct 31.
This work examines the dosimetric performance of two algorithms creating a corrected CBCT (corrCBCT) and a virtual CT (vCT) implemented in a commercial treatment planning system.
60 patients distributed across all patient groups treated with curative intent at Vejle Hospital (breast, lung, prostate and anal/rectal cancer) were selected for the present study. Clinical treatment plans were recalculated on corrCBCT and vCT, as well as a reference CT (refCT) acquired as close in time to the CBCT image as possible. Recalculated doses were compared using gamma analysis, as well as by comparing D, D, and D for all delineated targets and organs at risk.
High dosimetric accuracy is demonstrated on both the corrCBCT and vCT. Gamma 2%/2mm pass rates >98% were found for all patients except two outliers still having >93% pass rates. Equivalence of all evaluated dose metrics within ±1Gy was observed for all patient groups, while the pelvic patients additionally showed equivalence for all metrics within ±1% of the refCT dose. For the thoracic patients, equivalence within ±2.5% was established for all metrics except median dose to the ipsilateral lung, calculated on corrCBCT for the breast patient group.
The corrCBCT and vCT images are shown in excellent dosimetric agreement with refCT images, and show high potential for future use for streamlined adaptive radiotherapy workflows.
本研究旨在考察两种算法（校正 CBCT（corrCBCT）和虚拟 CT（vCT））在商业治疗计划系统中的剂量学性能。
本研究选取了在维泽勒医院接受根治性治疗的 60 名患者（乳腺癌、肺癌、前列腺癌和肛门/直肠癌），这些患者分布在所有患者组中。临床治疗计划在 corrCBCT 和 vCT 上重新计算，并在尽可能接近 CBCT 图像采集时间的情况下在参考 CT（refCT）上重新计算。使用伽马分析以及比较所有勾画靶区和危及器官的 D、D 和 D 来比较重新计算的剂量。
在 corrCBCT 和 vCT 上均显示出高剂量学准确性。除了两个仍有 >93%通过率的离群值外，所有患者的伽马 2%/2mm 通过率均>98%。所有患者组的所有评估剂量指标均在±1Gy 内等效，而骨盆患者在 refCT 剂量的±1%内还显示出所有指标的等效性。对于胸部患者，除了在乳腺癌患者组中计算 corrCBCT 上的同侧肺中位数剂量外，所有指标的等效性均在±2.5%内。
校正 CBCT 和虚拟 CT 图像与参考 CT 图像在剂量学上具有极好的一致性，并且在未来简化自适应放疗工作流程方面具有很高的应用潜力。
