Independent favorable prognostic factor for intracranial PFS* and OS

Outcome	Variable	Hazard ratio	95% CI	P
Intracranial PFS	SRS and nivolumab	0.54	0.32–0.92	0.038
Intracranial PFS	fmulti-fraction SRS	0.48	0.28–0.87	0.015
OS	SRS and nivolumab	0.51	0.28–0.81	0.019
	multi-fraction SRS	0.54	0.33–0.96	0.043
	KPS >70	0.34	0.23–0.78	0.010
	absent extracranial disease	0.50	0.29–0.81	0.018

Abbreviations: OS, overall survival; PFS, progression-free survival;HR, hazard ratio; CI, confidence interval; *Variables with a significance of p < 0.05 at univariate analysis were included in the multivariate analysis. The following variables were evaluated: age, gender, Karnofsly Perforance Status (KPS) score, histology, extracranial disease status, systemic therapy, number of metastases, time to brain metasases development, conformity index, and irradiated volumes