Early versus late prophylactic cranial irradiation in patients with extensive small cell lung cancer

Previous studies demonstrated that prophylactic cranial irradiation (PCI) significantly reduced the incidence of brain metastases in patients with extensive disease small cell lung cancer (ED-SCLC). However, the appropriate timing for PCI in treating ED-SCLC is still unclear. This study aimed to compare the effect and safety of early versus late PCI. Between November 2011 and July 2016, 103 patients with ED-SCLC were reviewed, receiving appropriate imaging tests to exclude brain metastases prior to cranial irradiation. Of these 103 patients, early PCI was performed in 47 patients and the other 56 patients received late PCI. The primary endpoint was the incidence of brain metastases. The progression-free survival (PFS), overall survival (OS), and adverse events (AEs) were also assessed. Early PCI significantly lowered the risk of brain metastases, as compared to late PCI (paEuro= 0.024). Additionally, multivariate analyses demonstrated that early PCI was a favorable independent predictor of the incidence of brain metastases. The PFS and OS of patients in the early and late PCI groups were comparable (PFS: 8.4 months vs. 7.5 months, paEuro0.753). The AEs were generally acceptable in both groups. To reduce the incidence of brain metastases, early PCI is more effective than late PCI for ED-SCLC patients.