Fig. 6From: Comparisons of volumetric modulated arc therapy (VMAT) quality assurance (QA) systems: sensitivity analysis to machine errorsROC analysis of gantry angle errors. a, b and c are for gantry angle error magnitude of 1°, 2° and 3°, respectively. d AUC vs. error magnitude. Curves with AUC of 1.0 reduce to a single point on upper left corner. 1°–3° ATA thresholds were chosen for EPID techniqueBack to article page