Dosimetric benefits of automation in the treatment of lower thoracic esophageal cancer: Is manual planning still an alternative option?

摘要

Abstract 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 ? max ) 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 5 ) for the lung ( p ?=?0.005). For auto-planning, the V 5 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 5 of the lung, and the low dose distribution was highly associated with PTV volume and lung volume in auto-planning.