Dosimetric analysis
The DICOM files of submitted plans were imported into MIM software (Cleveland, OH) for review. All plans were reviewed by at least one experienced radiation oncologist and one specialized dosimetrist in the QA team. The plans were evaluated regarding the homogeneity and conformality of PTV, dose to OARs, beams arrangement, skin flash, inhomogeneity corrections, space for improvement, and the results of dosimetric verification. Major deviations such as inappropriate beam arrangement were defined by the radiation oncologists and dosimetrists during review. The protocol compliance and the actual value of each parameter were assessed in the first and final submission, respectively. Statistical analyses were computed using SPSS 22.0 (IBM Corporation, Armonk, NY, USA). Mc-Nemar test was used for paired differences between the first and final submission. Two-sided P < 0.05 indicated statistically significances.