Background and purpose: Radiation therapy is still the most primary treatment of brain metastases

and prognosis is affected by many factors. The aim of this study was to identify the prognostic factors and to establish a prognostic index model in patients with brain metastases after whole-brain radiotherapy (WBRT). Methods: We reviewed the clinical date of 140 patients with brain metastases radiotherapy in our hospital from Jan. 2008 to Jul. 2011. The significance of prognostic variables in the survival was resulted from both univariate analysis and multivariate analysis. The prognostic index (PI) was established based on Cox regression analysis and subgrouping values. It was assessed whether recursive partitioning analysis classes (RPA)

basic score for brain metastases (BSBM) and the graded prognostic assessment index (GPA) were related to prognosis. Results: The median survival time was 222 days. The univariate analysis showed that the independent prognostic factors were KPS performance status

number of brain metastases

presence of extracranial metastases

primary tumor status

radiation dose

hemoglobin. The multivariate analysis showed that KPS performance status (P=0.002

Wald=9.700)

presence of extracranial metastases (P=0.018

Wald=5.604) and primary tumor status (P=0.001

Wald=10.212) were significantly correlated with overall survival. RPA

BS-BM and GPA were closely related to their prognosis by Log-rank test. In predicting 3 months and 6 months of survival for patients

PI was better than other modes. Conclusion: Our data suggest that the 3 indexes RPA

BS-BM and GPA are valid prognostic index models

but PI model is better.