Prophylactic cranial irradiation for extensive-stage small cell lung cancer: Analysis based on active brain MRI surveillance

BACKGROUND AND PURPOSE: The value of prophylactic cranial irradiation (PCI) for extensive-stage small-cell lung cancer (ES-SCLC) has recently been challenged. This study was conducted to evaluate the role of PCI for ES-SCLC under active brain magnetic resonance imaging (MRI) surveillance. MATERIALS AND METHODS: Patients with ES-SCLC who showed any responses after first-line chemotherapy and no initial brain metastasis (BM) were retrospectively included. Active brain MRI surveillance was performed for all patients. Progression-free survival (PFS) and overall survival (OS) were compared between PCI and non-PCI patients. The time-related hazard of BM was evaluated in non-PCI patients. RESULTS: One hundred and eighteen consecutive patients were included in the study. The median follow-up time was 26.5 months (3–72 months). The median PFS and OS were better in the PCI cohort than in the non-PCI group. Multivariate analyses revealed first-line chemotherapy cycles (> 4 vs. ≤ 4 cycles, HR: 0.29; 95% CI: 0.15–0.55, P < 0.01) and PCI (Yes vs. No, HR: 0.54; 95% CI: 0.29–0.99, P = 0.04) were independent prognostic factors for disease progression. In the non-PCI group, 47.4% (46/97) of the patients developed BM and the hazard of BM increased continuously in three-quarters of the first year since diagnosis. CONCLUSION: Under active brain MRI surveillance, PCI could be beneficial for patients with ES-SCLC who show good responses after first-line chemotherapy.