CyberKnife radiosurgery for brainstem metastases: Management and outcomes and a review of the literature.

•This is the first paper to use recursive partitioning analysis (RPA) for brainstem metastasis (BSM) outcomes after CyberKnife radiosurgery (CKRS).•Nine previous publications analyzed BSM patients using RPA but were mainly after Gamma Knife radiosurgery (GKS).•5 median single session equivalent dose (SSED), 13 less than SSED and 17 greater than SSED-treated BSM had LC in 4 (80%), 10 (77%) and 14 (82%).•54 RPA Class II/III BSM patients had a median OS of 5months and for each Class, 8 and 2 months respectively.•Univariate analysis showed that Karnofsky Performance Status, RPA Class and extracranial systemic disease-control predicted OS.