Outcome After Radiosurgery for Brain Metastases in Patients With Low Karnofsky Performance Scale (KPS) Scores

Purpose: The objective of this retrospective study was evaluation of the outcome after stereotactic radiosurgery (SRS) in patients with intracranial metastases and poor performance status. Methods and Materials: Forty consecutive patients with metastatic brain tumors and Karnofsky performance scale (KPS) scores ≤50 (mean, 43 ± 8; median, 40) treated with SRS were analyzed. Poor performance status was caused by presence of intracranial metastases in 28 cases (70%) and resulted from uncontrolled extracerebral disease in 12 (30%). Results: Survival after SRS varied from 3 days to 11.5 months (mean, 3.8 ± 2.9 months; median, 3.3 months). Survival probability constituted 0.50 ± 0.07 at 3 months and 0.20 ± 0.05 at 6 months posttreatment. Cause of low KPS score (p = 0.0173) and presence of distant metastases beside the brain (p = 0.0308) showed statistically significant associations with overall survival in multivariate Cox proportional hazards regression analysis. Median survival was 6.0 months if low KPS score was caused by cerebral disease and distant metastases in regions beyond the brain were absent, 3.3 months if low KPS score was caused by cerebral disease and distant metastases in regions beyond the brain were present, and 1.0 month if poor performance status resulted from extracerebral disease. Conclusions: Identification of the cause of low KPS score (cerebral vs. extracerebral) in patients with metastatic brain tumor(s) may be important for prediction of the outcome after radiosurgical treatment. If poor patient performance status without surgical indications is caused by intracranial tumor(s), SRS may be a reasonable treatment option.