MTSBM: median time interval between the diagnosis of lung cancer and the detection of subsequent brain metastases; BM: brain metastases; NSCLC: non-small cell lung cancer; SBM: subsequent BM; Patient no.: patient number; WT: wild-type; Mut: mutated; EGFR: epidermal growth factor receptor; NR: not reached. The MTSBM was estimated using the Kaplan- Meier method and group difference (i.e., EGFR mutations) was compared using log-rank tests.