RADT-02. WHOLE-BRAIN RADIATION THERAPY WITH SIMULTANEOUS INTEGRATED BOOST VERSUS STEREOTACTIC RADIOTHERAPY FOR THE TREATMENT OF BRAIN METASTASIS FROM NON-SMALL CELL LUNG CANCER

Abstract OBJECTIVE To compare whole-brain radiotherapy with a simultaneous integrated boost (WBRT-SIB) to stereotactic radiotherapy (SRT) in treating non-small cell lung cancer (NSCLC) patients with brain metastases (BMs). METHODS Between April 2013 and June 2021, NSCLC patients receiving WBRT-SIB or SRT for 1-10 BMs were reviewed. Propensity score matching was carried out without replacement using a ratio of 1 WBRT-SIB: 1 SRT patient and a caliper width of 0.03 to yield sufficient power and homogeneity between treatment groups. Intracranial progression-free survival (iPFS), overall survival (OS), the cumulative incidence of local tumor progression, and intracranial distant tumor progression were compared between groups. Toxicities were assessed utilizing the National Cancer Institute Common Terminology Criteria for Adverse Events Version 5.0 (CTCAE 5.0). RESULTS A cohort of 181 patients with was included in this study. After propensity score matching, there were 37 patients in the WBRT-SIB and the SRT group, respectively. The WBRT-SIB group had a significantly longer median iPFS than the SRT group (10.8 months vs. 6.5 months, p = 0.018). The median OS (p = 0.861) and the cumulative incidence of local tumor progression (p = 0.437) were similar between the two groups. WBRT-SIB was associated with reduced intracranial distant tumor progression (p = 0.043). No toxicities higher than grade 3 were observed in both groups. KPS score was an independent prognostic factor of OS (HR 0.459, p = 0.032). CONCLUSIONS Compared to SRT, the iPFS of NSCLC patients with BMs was prolonged after WBRT-SIB, mainly related to better control of distant intracranial tumors. WBRT-SIB is safe and can be an alternative option for patients with BMs. We also found that the KPS score is an independent prognostic factor of OS.