brain metastasescheckpoint inhibitorsimmunotherapymelanoma brain metastasesmetastatic melanomastereotactic radiotherapyPOSTOPERATIVE STEREOTACTIC RADIOSURGERYCLINICAL-PRACTICE GUIDELINESOPEN-LABELCEREBRAL METASTASESMALIGNANT-MELANOMASURGICAL RESECTIONMULTICENTERMANAGEMENTPROGNOSISPHASE-3