A graded prognostic assessment scale to predict overall survival in patients diagnosed with brain metastases undergoing Gamma-knife radiosurgery

Background: The present study aims to evaluate the Graded Prognostic Assessment (GPA) score for predicting overall survival in patients diagnosed with brain metastases undergoing Gamma-knife radiosurgery. Methods: This was a cross sectional study conducted on the patients diagnosed with brain metastases undergoing Gamma-knife radiosurgery during 2003 to 2011. Clinical and radiological parameters were evaluated, and the GPA score were determined. Kaplan–Meier and log-rank tests were used to assess prognostic factors of the GPA. Results: Two hundred and twenty patients were eligible to enter the study during the eight years course of study. The mean age of the patients was 54 ± 12.7 years (ranged 19 to 82 years) and were followed up for an average of 7 (range=1-25) months post Gamma-knife surgery. Median survival times according to the GPA were: GPA 0–1, 4 ± 0.4 months; GPA 1.5–2.5, 6 ± 0.7 months; GPA 3, 9 ± 0.9 months; and GPA 3.5–4.0, 12 ± 1.8 months and overall survival were 7 ± 0.6 months. The level of statistical significance among GPA groups was p less than 0.0001. Conclusion: It seems that the preoperative GPA is able to predict Gamma-knife radiosurgery results in patients with brain metastases. However, the results should be confirmed with further clinical trial assessments.