Dosimetry study of Auto-VMAT planning and Manual-VMAT planning based on Pinnacle(3) 9.10 in radiotherapy for cervical cancer

The purpose of this study was to compare the dose distribution characteristics of automatic volume-modulated arc therapy (Auto-VMAT) planning and manual volume-modulated arc therapy (Manual-VMAT) planning of Philips Pinnacle(3) 9.10 planning system, to provide a basis for optimal radiation therapy planning for cervical cancer. Ten patients with cervical cancer in our hospital from September to December 2018 were selected, and 2 treatment plans, Auto-VMAT plan and Manual-VMAT plan, were designed using Pinnacle(3) 9.10 planning system, respectively, to evaluate the maximum dose Dmax, mean dose Dmean, homogeneity index of the target area according to the dose volume histogram, the conformability index, plan optimization time, monitor units (MUs), organ at risk and other indicators. The results were that the Auto-VMAT plan was superior to the Manual-VMAT plan for target area Dmean, conformability index, and homogeneity index, with statistically significant differences (P < .05) and no significant difference in maximum dose Dmax (P > .05); rectal V40, V50, and Dmean in the Auto-VMAT plan, bladder V40, V50, and Dmean, small bowel V30, V40, V50 and Dmean, and right and left femoral V50 and Dmean were all lower than the Manual-VMAT plan, and the difference was statistically significant (P < .05); the mean optimization time for the Auto-VMAT and Manual-VMAT plans was 47 minutes and 35 minutes, respectively, an increase of 34%. The average number of MUs was 519 MUs and 374 MUs, respectively, an increase of 28%. This study concluded that the Pinnacle(3) 9.10-based Auto-VMAT plan was clinically feasible and significantly superior to the Manual-VMAT plan in terms of improved target area uniformity and conformability and reduced organ endangerment dose while reducing the impact of human factors on the quality of plan design.