Accuracy and workflow efficiency of surface-guided open-face vs. closed-face masks in SRT/SRS for brain metastases.

Abstract

BackgroundOpen-face masks (OFMs) provide comparable immobilization or superior accuracy with greater patient comfort than closed-face masks (CFMs), but their impact on workflow efficiency in stereotactic radiotherapy (SRT) and radiosurgery (SRS) for brain metastases remains unclear. This study compared immobilization accuracy, setup-related interruptions, and workflow efficiency of OFM with surface-guided radiotherapy (SGRT) versus CFM.MethodsWe retrospectively analyzed 180 consecutive SRT/SRS courses for brain metastases (March 2020-February 2024) using OFM/SGRT or CFM. Setup accuracy, repeat imaging, repositioning, and session duration were extracted from treatment and CBCT records. Translational and rotational errors were compared using Mann-Whitney U-tests; session times with t-tests.ResultsOFM/SGRT achieved smaller mean x- (1.1 ± 1.0 vs. 1.3 ± 1.1 mm) and z-axis displacements (0.7 ± 0.7 vs. 1.3 ± 1.1 mm) but slightly larger y-axis displacement (2.0 ± 1.7 vs. 1.4 ± 1.4 mm; all p ConclusionsOFM combined with SGRT provides improved rotational stability and comparable translational setup accuracy overall compared with CFMs in SRT/SRS, despite inferior longitudinal (y-axis) accuracy. OFM/SGRT was associated with fewer setup-related deviations during initial positioning. While overall session durations were comparable between workflows, reduced setup-related interruptions were observed with OFM/SGRT. These findings support OFM/SGRT as a clinically viable and patient-friendly alternative to conventional CFMs in SRT/SRS.