Institute of Modern Physics, Fudan University, Shanghai, China.
Department of Radiation Oncology, Shanghai Chest Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
J Xray Sci Technol. 2024;32(2):379-394. doi: 10.3233/XST-230176.
This study aims to assess the dosimetry and treatment efficiency of TaiChiB-based Stereotactic Body Radiotherapy (SBRT) plans applying to treat two-lung lesions with one overlapping organs at risk.
For four retrospective patients diagnosed with two-lung lesions each patient, four treatment plans were designed including Plan Edge, TaiChiB linac-based, RGS-based, and a linac-RGS hybrid (Plan TCLinac, Plan TCRGS, and Plan TCHybrid). Dosimetric metrics and beam-on time were employed to evaluate and compare the TaiChiB-based plans against Plan Edge.
For Conformity Index (CI), Plan TCRGS outperformed all other plans with an average CI of 1.06, as opposed to Plan Edge's 1.33. Similarly, for R50 %, Plan TCRGS was superior with an average R50 % of 3.79, better than Plan Edge's 4.28. In terms of D2 cm, Plan TCRGS also led with an average of 48.48%, compared to Plan Edge's 56.25%. For organ at risk (OAR) sparing, Plan TCRGS often displayed the lowest dosimetric values, notably for the spinal cord (Dmax 5.92 Gy) and lungs (D1500cc 1.00 Gy, D1000cc 2.61 Gy, V10 Gy 15.14%). However, its high Dmax values for the heart and great vessels sometimes exceeded safety thresholds. Plan TCHybrid presented a balanced approach, showing doses comparable to or better than Plan Edge without crossing safety limits. In terms of beam-on time, Plan TCLinac emerged as the most efficient treatment option in three out of four cases, followed closely by Plan Edge in one case. Plan TCRGS, despite its dosimetric advantages, was the least efficient, recording notably longer beam-on times, with a peak at 33.28 minutes in Case 2.
For patients with two-lung lesions treated by SBRT whose one lesion overlaps with OARs, the Plan TCHybrid delivered by TaiChiB digital radiotherapy system can be recommended as a clinical option.
本研究旨在评估基于太极 CT 直线加速器的立体定向体部放射治疗（SBRT）计划治疗两个重叠的肺病变和一个危及器官的剂量学和治疗效率。
对四名诊断为两个肺病变的回顾性患者，每个患者设计了四个治疗计划，包括计划边缘、基于太极 CT 直线加速器的计划、基于 RGS 的计划和基于直线加速器-RGS 混合的计划（计划 TCLinac、计划 TCRGS 和计划 TCHybrid）。采用剂量学指标和照射时间来评估和比较基于太极 CT 直线加速器的计划与计划边缘的差异。
在适形指数（CI）方面，计划 TCRGS 优于所有其他计划，平均 CI 为 1.06，而计划边缘为 1.33。同样，在 R50%方面，计划 TCRGS 也表现出色，平均 R50%为 3.79，优于计划边缘的 4.28。在 D2cm 方面，计划 TCRGS 也以平均 48.48%领先，而计划边缘为 56.25%。在危及器官（OAR）保护方面，计划 TCRGS 通常显示出最低的剂量学值，特别是对于脊髓（Dmax 5.92Gy）和肺（D1500cc 1.00Gy，D1000cc 2.61Gy，V10Gy 15.14%）。然而，其心脏和大血管的高 Dmax 值有时超过了安全阈值。计划 TCHybrid 表现出一种平衡的方法，显示出与计划边缘相当或更好的剂量，而不会超过安全限制。在照射时间方面，计划 TCLinac 在四种情况下有三种是最有效的治疗选择，在一种情况下紧随计划边缘之后。尽管计划 TCRGS 在剂量学方面具有优势，但它是最不有效的，特别是在第二种情况下，记录的照射时间明显更长，峰值为 33.28 分钟。
对于接受 SBRT 治疗的两个肺病变患者，其中一个病变与 OAR 重叠，太极 CT 数字放射治疗系统提供的计划 TCHybrid 可以作为一种临床选择。
