Outcomes of single brain metastasis treated with gamma knife stereotaxic radiosurgery(GKSR). Our experience on 103 cases

Background: Brain metastases (BM) occur in the natural course of malignant tumors in 18–40% of cases. Their management has changed considerably over the past decade thanks to the advent of Gamma knife Stereotactic Radiosurgery (GKSR). Objective: We report our experience on Single Brain metastasis treated with (GKSR). Methods: Patients treated by Gamma Knife stereotaxic radiosurgery (GKSR) in our institution between 2009 and 2021 for Single BM were recorded retrospectively. Results: A total of 103 patients (n = 52; 50.5% females) were included, with a mean age of 56.33 ± 11.33. Breast (n = 39, 37.9%) and lung (n = 36, 35%) were the common original location for the primary tumors. GKSR alone without prior surgery, radiotherapy, or chemotherapy was achieved in 81.5% (n = 84). Thirteen patients (15.1%) progressed in BM volume while finding the appearance of de novo BM in 5 (5.8%) patients. The median percentage of tumor control after radiosurgery treatment was 70% (IQR: 65–78) and only 26.2% (n = 27) of patients had > 80% tumor control and stability over the median follow-up time of 5 (95% CI, 4–6) months. We found only two cases of radionecrosis (1.9%). The median survival time was 5.21 (IQR, 3–8) months. Retreatment, recursive partitioning analysis (RPA) class, and tumor stability influenced the overall survival of BM respectively (Hazard Ratio adjust (HRa)= 5.610,p = 0.045; HRa= 6.133,p = 0.031; HRa= 22.463, p = 0.036). Conclusion: Stereotaxic Radiosurgery provides good results in terms of Overall survival with fewer neurocognitive disorders.RPA class and tumor control (stability) influenced the overall survival of single BM