Stereotactic radiosurgery for brain metastases from small cell lung cancer without prior whole-brain radiotherapy: A meta-analysis

Abstract

ObjectivesAssess upfront Stereotactic radiosurgery (SRS) effectiveness for small cell lung cancer (SCLC) brain metastases (BM). Where possible, a comparison with whole-brain radiotherapy (WBRT) was performed. MethodsFollowing PRISMA and MOOSE guidelines, eligible studies were identified on Medline, Embase, Cochrane Library, and proceedings of annual meetings between inception and July 01, 2020. ResultsNine observational studies with 1638 patients were included. The median overall survival (OS) was 8.3 months (95% CI 7.1–9.5 months, I2 = 0%). OS rate at 12 months was 39% (95% CI 31–44%, I2 = 0%). The relative risk between SRS and WBRT for the OS at 12 months was 1.33 (95% CI 1.13–1.51, P = 0.0001). The projected OS for 6, 12, 18- and 24-months comparing SRS with WBRT was 67% vs. 57%, 39% vs. 29%, 22% vs. 15% and 15% vs 9%, favoring SRS (P < 0.001). The LC rate at 12 months was 93% (95% CI 91–94%, I2 = 0%). The distant brain failure rate (DBFR) at 12 months was 41% (95% CI 33–48%, I2 = 52%, P = 0.08). The SRS or WBRT as salvage treatment after upfront SRS was 32% and 19%, respectively. The freedom from neurologic death at 12 months was 87% (95% CI 84–89%). ConclusionBased on the pooling of a large sample of retrospective studies our meta-analysis suggests that for high selected SCLC patients with limited BM upfront SRS produces favorable lesion control and survival outcomes. These findings support the design of randomized clinical trial to confirm the role of SRS in this clinical scenario.