LMAP-03 OUTCOME OF BRAIN METASTASES TREATED WITH GAMMA KNIFE STEREOTACTIC RADIOSURGERY (GKSR): COHORT RETROSPECTIVE STUDY ON 205 CASES

BACKGROUND: Brain metastases (BMs) are the most common expansive intracranial lesions in adults. Approximately 50% of patients diagnosed with new brain metastases have more than one brain metastasis at the time of diagnosis. OBJECTIVE: We report our experience of brain metastases treated with GKSR and evaluate the outcome. METHODS: Patients treated by Gamma Knife stereotactic radiosurgery (GKSR) in our institution between 2008 and 2021 for BM were recorded retrospectively. RESULTS: A total of 205 patients (56.6% females) were included, with a median age of 59 (25-83) years old. Breast (n=85, 42.5%) and lung (n=76, 38%) were the common original locations for the primary tumors (Table 1). There were 103 patients (50.3%) with single BM and 102 patients (49.7%) with multiple BM⩾2. The median number of multiple BM treated was 4 (2-43). The overall mean survival time was 6.00(95% CI, 5.07-6.93) months for all BM. The median percentage of tumor control after radiosurgery treatment was 65% (20-99) over the median follow-up time of 6.00(3-84) months. In the overall population, the 1-year OS rate was 37.55%, the 2-year OS rate was 25.12%, and the 5-year OS was 18.51%. The mean survival time among patients with BM was higher in those with multiple BM than those with single BM ([10 (95%CI 6.67-13.33) months vs 5(4.21-5.70) months, P (0.03)]). Retreatment, tumor stability (control), and progression influence the overall survival of BM, whether single or multiple (P<0.001). CONCLUSION: Stereotaxic Radiosurgery provides good results in terms of Overall survival and better Quality of Life for BM, whether single or multiple. Stability and retreatment influenced the overall survival of BM.