Intracranial control and survival outcome of tyrosine kinase inhibitor (TKI) alone versus TKI plus radiotherapy for brain metastasis of epidermal growth factor receptor-mutant non-small cell lung cancer

Introduction The efficacy of tyrosine kinase inhibitors (TKIs) with and without radiotherapy (RT) has not been determined in patients with brain metastases from epidermal growth factor receptor-mutant TKI naïve non-small cell lung cancer (NSCLC). Methods Between 2008 and 2016, 586 patients were diagnosed with NSCLC and treated with TKIs at a hospital in Seoul, South Korea; 81 of these patients met the eligibility criteria for our study. Outcomes analyzed included intracranial progression (ICP), neurological death, and overall survival (OS). Results The 2-year cumulative incidence of ICP was 36.5% in the TKI plus RT group and 62.2% in the TKI alone group (P = 0.006). The chronological pattern analysis indicated that 64.3% of ICP developed within 12 months of the start of TKI treatment in the TKI alone group. The multivariate analysis revealed that treatment group (P = 0.003) and duration of TKI treatment ≤ 12 months (P