ИСТИНА

Objective: The number of brain metastases (BMs) plays an important role in the decision making between stereotactic radiosurgery (SRS) and whole-brain radiation therapy Methods: We analyzed the survival of 457 SRS-treated patients with BM as a function of BM number. 113 (24.7%) patients were treated with repeat SRS for local recurrence and distant brain relapse. Survival analyses were performed with Kaplan-Meier analysis as well as univariate and multivariate Cox proportional hazards models. Results: The median survival for all patients was 9.8 months (95% CI 8.5-11.3). Patients with BMs were categorized as those with 1, 2-4, 5-9 and ≥10 BMs. Median overall survival for patients with 1 BM was superior to those with 2-4, 5-10 and >10 BMs (14.3 months vs. 10.5 months vs. 6.6 months vs. 7.2 months, р= 0,0001). Survival of patients with 5-9 BMs did not differ from those with >10 BMs (6.6 months vs. 7.2 months, p=0.8288). Аccording to multivariate analysis, age younger than 50 years (p = 0.005, HR 0.59, 95% CI 0.41 - 0.86), number of lesions ≥5 (p = 0.02, HR 1,44, 95% CI 1,05 - 1.95), Karnofsky performance status ≥80 (p < 0.0001, HR 0.52, 95% CI 0.38 - 0.69) аnd absence of extracranial metastases (p < 0.01, HR 0.56, 95% CI 0.35 - 0.90) had significant impacts on overall survival. Conclusions: The contribution of BM number to overall survival is modest and should be considered as one of the many variables considered in the decision between SRS and whole-brain radiation therapy. Our finding confirm correlation between the survival outcome and the number of lesions treated SRS. According to our data, the median survival of patients with 2-4 metastases in the brain is significantly higher compared with a group of patients who have 5-10 or more lesions.