Dosimetric Impact of Using a Virtual Couch Shift for Online Correction of Setup Errors for Brain Patients on an Integrated High-Field Magnetic Resonance Imaging Linear Accelerator

For translational errors in brain MRI-linac radiation therapy, the VCS method is an acceptable correction strategy, but caution must be used in particular for serial organs where maximum doses are most relevant. The effect of the magnetic field on relative changes between corrected versus reference plans is not clinically relevant.