Preliminary application and discussion of independent 3D dose calculation in intensity-modulated radiotherapy for cervical cancer / 中华放射肿瘤学杂志

ABSTRACT

Objective To assess the feasibility for the automated treatment planning verification system Mobius3D (M3D) to perform an independent 3D dose calculation in intensity-modulated radiotherapy (IMRT) for cervical cancer.Methods Twenty patients with cervical cancer were randomly selected.With treatment planning systems (Pinnacle,Version 9.2;Eclipse,Version 13.5),all IMRT plans were divided into 7 fields to meet the dosimetric goals.The optimized plans were exported to the M3D server.The percentage differences in the volume of region of interest (ROI) and the dose calculation of target volume and organ at risk (OAR) were evaluated for the two treatment planning systems,and theγ passing rate was used to assess the accuracy of M3D calculation.Results The difference in the volume of ROI for Pinnacle 9.2 to M3D was less than that for Eclipse 13.5 to M3D,with maximum differences of 0.22％±0.69％ and 3.5％±1.89％ for Pinnacle 9.2 and Eclipse 13.5,respectively.The differences in the dose calculation of target volume and OAR for the two treatment planning systems to M3D were within ± 1％.After recalculating by M3D,the dose difference between Pinnacle 9.2 and M3D was smaller than that between Eclipse 13.5 and M3D,but the mean differences were all within ±3％.The γ passing rates for target volume and OAR were more than 95％ on average.Conclusions The method of utilizing the automated treatment planning verification system to validate the accuracy of plans is convenient.It can be used as a secondary check tool to improve accuracy in IMRT dose calculation.