Prophylactic Cranial Irradiation in Limited-Stage Small Cell Lung Cancer: A Meta-Analysis

The role of prophylactic cranial irradiation (PCI) in limited-stage small cell lung cancer (LS-SCLC) has been questioned in the era of magnetic resonance imaging (MRI). The purpose of this study was to re-evaluate the efficacy of PCI in patients with LS-SCLC. Three electronic databases were searched, including PubMed, Embase, and the Cochrane Library from January 2012 to April 2022. All relevant publications were included based on the inclusion criteria, and survival data and brain metastasis (BM) rates were extracted and pooled. Ten studies were selected which involved 532 patients who received PCI and 613 patients who did not receive PCI. In pooled estimates, PCI significantly improved overall survival (OS) and progression-free survival (PFS) [hazard ratio (HR) = 0.71, 95% confidence interval (CI): 0.61-0.82, p <0.001; HR = 0.68, 95% CI: 0.48-0.97, p = 0.03, respectively]. Additionally, the use of PCI was associated with a significant reduction in the risk of brain metastasis (BM, risk ratio = 0.64, 95% CI: 0.46-0.90, p = 0.009). In subgroup analyses. The authors found that the PCI effects on OS were independent of region and the use of brain imaging after initial treatment. These findings demonstrate that PCI improves OS and PFS while decreasing the risk of BM in patients with LS-SCLC, implying that PCI remains necessary even in the MRI era. Key Words: Prophylactic cranial irradiation, Small cell lung cancer, Magnetic resonance imaging, Brain metastasis.