Table S1. The median proportion of baseline characteristics of the included studies.

Study	Sample	Female	Younger	Non-smoking	ECOG PS <2	19deletion	Limited number of BM	With BM-related symptom	Extra-cranial metastasis
Byeon 2016	121	0.69	0.66	0.77	0.72	0.61	0.3	0.33	0.81
Chen 2016	132	0.61	0.81	0.73	–	0.55	0.27	0.49	–
Fan 2017	97	0.56	0.57	0.68	–	0.59	0.51	0.27	0.73
Jiang 2016	121	0.53	0.69	0.65	0.86	0.55	0.04	0.16	–
Ke 2018	139	0.6	0.8	0.73	–	0.55	0.27	0.51	–
Li 2018	28	0.61	–	0.79	0.89	0.57	0.57	0.39	–
Liu 2017	113	0.65	0.65	0.76	0.81	0.41	0.17	0.47	–
Magnuson 2017 WBRT	251	0.67	0.5	0.34	0.75	0.65	0.46	0.31	0.22
Magnuson 2017 SRS	231	0.69	0.42	0.35	0.73	0.61	0.72	0.28	0.25
Sung 2018	81	0.52	0.57	0.11	0.84	–	0.58	0.11	–
Wang 2016	132	0.55	0.7	0.69	0.88	0.53	0.54	0	0.56
Zhu 2017	133	0.54	0.79	–	–	0.47	0.31	–	0.65
Chen 2018 concurrent RT	73	0.62	0.52	0.48	0.3	0.56	0.16	0.77	0.84
Chen 2018 upfront RT	71	0.59	0.49	0.46	0.34	0.56	0.15	0.76	0.82

WBRT, whole brain radiation therapy; SRS, stereotactic radiosurgery; RT, radiotherapy; BM, brain metastasis.