Effectivity of involved-field radiotherapy for recurrent brain metastasis in patients with small-cell lung cancer.

Abstract

To investigate the outcome difference of whole brain radiotherapy (WBRT) and involved-field radiotherapy (IFRT) in limited-stage small-cell lung cancer (LS-SCLC) patients with recurrent brain metastases (BMs) after prophylactic cranial irradiation (PCI). A retrospective analysis was carried out in 68 LS-SCLC patients who underwent WBRT or IFRT owing to the occurrence of recurrent BMs after PCI from 2009 to 2020. The median overall survival (OS) of all patients was 11.43 months [95% confidence interval (CI) 9.39-13.48 months]. In the paired comparison of OS, the IFRT group had a significantly longer survival time than the WBRT group in all patients [17.80 months vs. 8.47 months; hazard ratio (HR), 0.393, 95% CI, 0.213-0.728; P = 0.002] and 46 matched patients (18.23 months vs. 8.73 months; HR, 0.411, 95% CI, 0.195-0.865; P = 0.019). In terms of the intra-cranial progression-free survival (iPFS), there was no significant difference between the WBRT group and IFRT group before matching (5.93 months vs. 7.30 months; HR, 0.644, 95% CI, 0.373-1.112; P = 0.111); similarly, no statistical difference was detected between the WBRT group and IFRT group after matching (5.33 months vs. 8.10 months; HR, 0.623, 95% CI, 0.323-1.199; P = 0.152). Meanwhile, of the 41 patients with symptoms, 27 cases (65.9%) had symptom relief, showing tolerable toxicity without unexpected toxicity during the observation. Compared with WBRT, IFRT exhibits better survival benefits for LS-SCLC patients with recurrent BMs after PCI. Re-irradiation for BMs exhibits advantages of symptom relief and tolerable side effects.