Effects of high-resolution measurements between different multi-row detectors on volumetric modulated arc therapy patient-specific quality assurance

Background: this study aimed to evaluate the optimal criteria and conditions in which single-measurement (sm) and high-resolution measurement (hm) provide a similar evaluation accuracy for arccheck (ac) and octavius (ot) detectors. materials and methods: in the sm and hm for ac and ot, we evaluated γ-analysis pass-rate differences for various conditions (criteria, calculation grid size, and shift of the isocenter) of 20 patients who received volumetric modulated arc therapy. all results of the γ-analysis pass rate were analyzed using the anderson–darling normality test. results: in the ac detector, an sm with a 1%/1 mm criterion, 1.25 mm calculation grid size, and two standard deviations (2sd) of tolerance showed an evaluation accuracy similar to that of an hm. in the ot detector, an sm with a 2%/2 mm criterion, 2.0 mm calculation grid, and 2sd of tolerance had an evaluation accuracy similar to that of an hm. the γ-pass-rate data of the ot detector for the 3%/3 mm criterion did not follow a normal distribution in both sm and hm. conclusions: most high γ-analysis pass rates achieved using inadequate criteria may not detect errors; therefore, accurate evaluation is necessary for optimizing the criteria settings of individual qa devices based on the characteristics and the uncertainties of array detectors. the characteristics of a detector array can be enhanced by evaluating the relationship between sm and hm, which reduces the workload of patient-specific qa.