Li Xiadong, Wang Lu, Wang Jiahao, Han Xu, Xia Bing, Wu Shixiu, Hu Weigang
Department of Radiation Oncology, Hangzhou Cancer Hospital, Hangzhou, Zhejiang, China.
Department of Gynecology and Obstetrics, Hangzhou Women's Hospital, Hangzhou Maternity and Child Health Care Hospital, Hangzhou, Zhejiang, China.
Med Dosim. 2017;42(4):289-295. doi: 10.1016/j.meddos.2017.06.004. Epub 2017 Jul 25.
This study aimed to design automated volumetric-modulated arc therapy (VMAT) plans in Pinnacle auto-planning and compare it with manual plans for patients with lower thoracic esophageal cancer (EC). Thirty patients with lower thoracic EC were randomly selected for replanning VMAT plans using auto-planning in Pinnacle treatment planning system (TPS) version 9.10. Historical plans of these patients were then compared. Dose-volume histogram (DVH) statistics, dose uniformity, and dose homogeneity were analyzed to evaluate treatment plans. Auto-planning was superior in terms of conformity index (CI) and homogeneity index (HI) for planning target volume (PTV), significantly improving 8.2% (p = 0.013) and 25% (p = 0.007) compared with manual planning, respectively, and decreasing dose of heart and liver irradiated by 20 to 40 Gy and 5 to 30 Gy, respectively (p < 0.05). Meanwhile, auto-planning further reduced the maximum dose (D) of spinal cord by 6.9 Gy compared with manual planning (p = 0.000). Additionally, manual planning showed the significantly lower low-dose volume (V) for the lung (p = 0.005). For auto-planning, the V of the lung was significantly associated with the relative volume index (the volume ratio of PTV to the lung), and the correlation coefficient (R) and p-value were 0.994 and 0.000. Pinnacle auto-planning achieved superior target conformity and homogeneity and similar target coverage compared with historical manual planning. Most of organs at risk (OARs) sparing was significantly improved by auto-planning except for the V of the lung, and the low dose distribution was highly associated with PTV volume and lung volume in auto-planning.
本研究旨在利用Pinnacle自动计划设计胸段下段食管癌（EC）患者的自动容积调强弧形放疗（VMAT）计划，并将其与手动计划进行比较。随机选择30例胸段下段EC患者，在Pinnacle治疗计划系统（TPS）9.10版中使用自动计划重新规划VMAT计划。然后比较这些患者的历史计划。分析剂量体积直方图（DVH）统计数据、剂量均匀性和剂量同质性以评估治疗计划。自动计划在计划靶体积（PTV）的适形指数（CI）和均匀性指数（HI）方面更具优势，与手动计划相比分别显著提高了8.2%（p = 0.013）和25%（p = 0.007），心脏和肝脏的受照剂量分别降低了20至40 Gy和5至30 Gy（p < 0.05）。同时，与手动计划相比，自动计划使脊髓的最大剂量（D）进一步降低了6.9 Gy（p = 0.000）。此外，手动计划显示肺的低剂量体积（V）显著更低（p = 0.005）。对于自动计划，肺的V与相对体积指数（PTV与肺的体积比）显著相关，相关系数（R）和p值分别为0.994和0.000。与历史手动计划相比，Pinnacle自动计划实现了更好的靶区适形性和均匀性以及相似的靶区覆盖。除肺的V外，自动计划在大多数危及器官（OARs）的保护方面有显著改善，并且自动计划中的低剂量分布与PTV体积和肺体积高度相关。
