Table 2. Multivariate analysis for factors related to overall survival following re-WBRT.

Factor analyzed	Negative predictive factor	P value
Karnofsky performance status	≤70	0.012
Symptoms	Severe symptoms	0.008
Age	>60	0.901
Gender		0.602
Primary tumor site	Lung and others	0.341
RPA class		0.663
Interval between two course of WBRT	≤9 months	0.733
BEDcumulative	>130 Gy	0.235
Extracerebral metastasis	Yes	0.229
Response to re-WBRT	Yes	0.714

WBRT, whole brain radiation therapy; re-WBRT, re-irradiation WBRT; RPA, recursive partitioning analysis; BED, biological effective dose.