There is no consensus on the optimal treatment of patients with high-grade glioma, especially when patients have limited functioning performance at presentation (KPS ≤70). Therefore, there are varied practice patterns around pursuing biopsy, resection, or palliation (best supportive care). This study aims to characterize the impact of palliative care versus biopsy versus resection on survival and quality of life in these patients. Also, it will aim to determine if there is a subset of patients that benefit the most from resection or biopsy, for which outcome, and how they could be identified preoperatively. This study is an international, multicenter, prospective, 3-arm cohort study of observational nature. Consecutive HGG patients will be treated with palliative care, biopsy, or resection at a 1:3:3 ratio. Primary endpoints are: 1) overall survival, and 2) quality of life at 6 weeks, 3 months and 6 months after initial presentation based on the EQ-5D, EORTC QLQ C30 and EORTC BN 20 questionnaires. Total duration of the study is 5 years. Patient inclusion is 4 years, follow-up is 1 year.