 The patients who meet the selection criteria and who have accepted to participate at the study will answer different questionnaires of the study before radiosurgery and at 3, 6, 9 and 12 months after the treatment of brain metastases. Baseline examinations will be done before receiving the treatment during the hospitalisation for the Gamma Knife treatment, and then they will be repeated at the evaluation visits which are classically done every 3 months. MRIs will also be performed every 3 months. In this way, no additional travel or MRI will be carried out as part of the study. 