Patient-Specific Pre-Treatment VMAT Plan Verification Using Gamma Passing Rates

Continuous gantry motion, continuous beam modulation, and variable dose rate are used in volumetric modulated arc therapy (VMAT) to obtain highly conformal radiation distributions. Several errors during daily treatment can be sources of uncertainties delivery. These include monitor unit calculation other human mistakes. Due the excessively VMAT plan, intended distribution is not delivered perfectly, leading a mismatch between measured planned This necessitates an extensive effective quality assurance (QA) program for both machine patient. In this study, QA plan verification 62 head neck (HN) 19 prostate cases was done using Octavius 4D setup with its associating VeriSoft gamma analysis software. The plans showed maximum 3D passing 4 mm/3 % acceptance criteria, i.e., 99.7 HN cancer 99.5 cases. Local also performed regions. Furthermore, 2D analyses were carried out. Gamma respect different axis It known that transversal highest cases, 99.17 98.3 %, respectively. transverse came better fit distribution.