Table 3. Multivariate analysis.
LC, local control; DPFS, distant progression-free survival; OS, overall survival; HR, hazard ratio; HER2, human epidermal growth factor receptor 2; MFI, metastasis-free interval; BM, bone metastasis; EBM, extrabony metastasis; RT, radiation therapy; Gy10, biological equivalent dose in Gy with α/β = 10; WLRT, whole-lesion RT; MRTI, metastasis-to-RT interval.