Abstract
BACKGROUND: This study aims to compare the therapeutic efficacy of whole brain radiotherapy (WBRT) versus WBRT plus simultaneous integrated boost (WBRT + SIB) in patients with brain metastases (BMs) from small cell lung cancer (SCLC). METHODS: A retrospective analysis was conducted on 127 patients with BMs from SCLC who received brain radiotherapy between 2014 and 2023 at the Cancer Hospital of the Chinese Academy of Medical Science. Among them, 71 patients underwent WBRT (25.0-54.0 Gy in 10-21 fractions), while 56 patients received WBRT + SIB (SIB to metastases: 18.0-60.0 Gy in 5-20 fractions). The overall survival (OS), intracranial progression-free survival (iPFS), objective response rate (ORR), and local control rate (LCR) were evaluated to assess the efficacy of the treatments. RESULTS: With a median follow-up of 14.9 months, the median OS was significantly longer in the WBRT + SIB group compared to the WBRT group (18.0 vs. 11.7 months). Similarly, the iPFS was extended in the WBRT + SIB group (12.2 vs. 7.6 months). Kaplan-Meier analysis revealed that WBRT + SIB significantly improved OS in patients with SCLC of BMs (P = 0.009). Subgroup analysis indicated that male patients, age < 60 years old, and multiple intracranial metastases benefited more from WBRT + SIB. Interaction tests suggested that age significantly influence the efficacy of WBRT + SIB, with patients < 60 years old deriving more benefit (P = 0.049). Concurrent WBRT + SIB with anti-angiogenic targeted therapy significantly improved iPFS (P < 0.001). CONCLUSIONS: WBRT + SIB can prolong the OS in SCLC patients with BMs, with younger age and those receiving anti-angiogenesis therapy potentially achieving additional survival benefits.