Survival in relation to radiotherapeutic modality for brain metastasis: whole brain irradiation vs. gamma knife radiosurgery.

The purpose of this report is to evaluate and compare the survival of patients with brain metastasis (BRM) treated by whole brain irradiation (WBI) using linear energy accelerator (LINAC) and by stereotactic radiosurgery using gamma knife. This study consists of a series of 67 patients with BRM treated with WBI between 1998 and 1999 and 53 patients with BRM treated with gamma knife radiosurgery (GKRS) between 2000 and 2001. A retrospective study of the data was performed and the overall survival between these 2 groups was analyzed. The comparability of these 2 groups was tested by chi2 and t test values. Log-rank test was used in the survival comparison. The 1-year survival rate was 26.3% and 22.6%, and corresponding mean survival was 7.8 months and 6.7 months for WBI and GKRS groups, respectively. There was no statistically significant difference between these 2 groups' survival. It was evident from imaging defined lesions that with GKRS the lesions were reduced, stabilized, or disappeared in 89% of cases. Survival of patients with BRM treated with WBI or GKRS was similar in these series. The present study suggests that good tumor response by GKRS does not translate in longer patient survival.