Extensive-stage small cell lung cancer: Is prophylactic cranial irradiation necessary in the era of immunotherapy with MRI surveillance?

Abstract

Objective: The role of prophylactic cranial irradiation (PCI) in treating extensive-stage small-cell lung cancer (ES-SCLC) has been controversial. This study aimed to comprehensively analyze the efficacy of PCI for the treatment of ES-SCLC under active brain magnetic resonance imaging (MRI) surveillance.

Methods: Patients with ES-SCLC with no brain metastases (BM) confirmed by MRI at the time of diagnosis who responded well to first-line chemoimmunotherapy at three general hospitals were retrospectively included. Overall survival (OS), progression-free survival (PFS), and cumulative incidence of BM were compared between patients who underwent PCI and those who did not.

Results: In total, 66 consecutive patients treated between March 2019 and December 2021 were included in our dataset. Seventeen patients underwent PCI (PCI group) and 49 patients did not (non-PCI group). In comparison with the non-PCI group, PCI did not provide OS (median OS: 18.53 vs. 17.35 months, p = 0.28) or PFS (median PFS: 8.61 vs. 7.56 months, p = 0.41) benefits. When death was counted as a competing risk, the difference in the cumulative incidence rate of BM was not statistically significant (1-year: 12.79% vs. 38.09%; p = 0.14).

Conclusion: Compared to active MRI surveillance, first-line chemoimmunotherapy followed by PCI did not improve the prognosis of patients with ES-SCLC. Further studies are warranted to evaluate the therapeutic effects of PCI following chemoimmunotherapy.