The combination of magnetic resonance (MR) imaging and linear accelerators (linacs) into MRLinacs enables continuous MR imaging and advanced gated treatments of patients. Previously, a dose-rate transient (~8% reduced dose rate during the initial 0.5 s of each beam) was identified for a Viewray MRIdian MR-Linac (Klavsen et al, 2022). Here, the dose-rate transient is studied in more detail at four linacs of the same type at different hospitals. The implications of dose-rate transients …