Concurrent versus non-concurrent immune checkpoint inhibition with stereotactic radiosurgery for metastatic brain disease: a systematic review and meta-analysis.

Immune checkpoint inhibition (ICI) is an emerging immunotherapy for metastatic brain disease (MBD). Current management options include stereotactic radiosurgery (SRS), which has been shown to confer prognostic benefit in combination with ICI. However, the effect, if any, of ICI timing on this benefit is currently unclear. The aim of this study was to evaluate the effect of concurrent ICI with SRS on survival outcomes in MBD compared to non-concurrent ICI administered before or after SRS.