Tao Dan, Sun Lisi, Wang Lulu, Yang Lina, Zhou Wei, Tian Xiumei, Liu Xianfeng
Department of Radiation Oncology, Chongqing University Cancer Hospital, 181 Hanyu Road, Shapingba District, Chongqing, 400030, China.
Chongqing Key Laboratory of Translational Research for Cancer Metastasis and Individualized Treatment, Chongqing University Cancer Hospital, Chongqing, China.
Radiat Oncol. 2025 Jun 18;20(1):103. doi: 10.1186/s13014-025-02675-y.
Stereotactic ablative body radiotherapy (SABR) for ultra-central (UC) lung tumors is still challenging due to potentially severe complications caused by overdoses to critical mediastinal structures. This study aimed to compare the dosimetric advantages between volumetric modulated arc therapy (VMAT)-SABR and Helical Tomotherapy (HT)-SABR in UC lung lesions.
From August 14, 2019, to June 4, 2023, patients with ultra-central (UC) lung tumors who received SABR for lung tumors were enrolled in this study. Two different radiotherapy plans were created based on the CT datasets of each case on the Eclipse and Tomotherapy treatment planning systems respectively. All patients received 60 Gy in 8 fractions. The parameters for dose evaluation of the target volumes and organs at risk (OARs) were compared based on the data extracted from dose-volume histograms. All of the statistical analyses were performed with SPSS 17.0 software.
Compared with HT-SABR, VMAT-SABR significantly increased the D of the iGTV ( = 0.002) and the D, D, and D of the PTV ( = 0.000, 0.000, and 0.002, respectively). The values of D, 95% isodose volume, and GI of VMAT-SABR significantly decreased by 15.11%, 7.78%, and 20.65% ( = 0.000; 0.000; 0.000) respectively. The values of D of the spinal cord, spinal cord + 3 mm, esophagus, heart, trachea, proximal bronchial tree (Pbtree), and great vessels, and D of the Non-GTV Lung and ipsilateral Non-GTV Lung with VMAT-SABR were significantly lower than those of HT-SABR.
Our study revealed that VMAT-SABR showed a steeper dose falloff and lower dose of the OARs. VMAT-SABR is a potentially optimal modality to improve the therapeutic ratio compared to HT-SABR in patients with UC lung lesions.
对于超中央型（UC）肺肿瘤，立体定向消融体部放疗（SABR）仍具有挑战性，因为对关键纵隔结构的过量照射可能导致严重并发症。本研究旨在比较容积调强弧形放疗（VMAT）-SABR和螺旋断层放疗（HT）-SABR在UC肺病变中的剂量学优势。
从2019年8月14日至2023年6月4日，纳入接受SABR治疗肺肿瘤的超中央型（UC）肺肿瘤患者。分别基于Eclipse和螺旋断层放疗治疗计划系统上每个病例的CT数据集创建两种不同的放疗计划。所有患者接受8次分割共60 Gy的照射。根据从剂量体积直方图中提取的数据，比较靶区体积和危及器官（OARs）的剂量评估参数。所有统计分析均使用SPSS 17.0软件进行。
与HT-SABR相比，VMAT-SABR显著提高了内部大体肿瘤体积（iGTV）的D（=0.002）以及计划靶体积（PTV）的D、D和D（分别为=0.000、0.000和0.002）。VMAT-SABR的D、95%等剂量体积和梯度指数（GI）值分别显著降低了15.11%、7.78%和20.65%（=0.000；0.000；0.000）。VMAT-SABR的脊髓、脊髓+3 mm、食管、心脏、气管、近端支气管树（Pbtree）和大血管的D值，以及非GTV肺和同侧非GTV肺的D值均显著低于HT-SABR。
我们的研究表明，VMAT-SABR显示出更陡峭的剂量下降和更低的OARs剂量。与HT-SABR相比，VMAT-SABR可能是提高UC肺病变患者治疗比的一种潜在最佳方式。
