Local Ablative Therapy for Patients With Multiple (4-10) Brain Metastases

Inclusion Criteria: 1. Male or female, ≥ 18 years of age 2. Minimal 4 and up to a maximum of 10 synchronous BM diagnosed on a high resolution contrast-enhanced MRI scan (T1 gadolinium) not dated more than 4 weeks prior to inclusion. 3. Maximal lesion diameter of single gross tumor volume (GTV) of 3 cm 4. Maximal cumulative GTV (+CTV for cavity) of 30cm3 5. Karnofsky performance status ≥ 70 6. DS-GPA or expected overall survival (if no DS-GPA applicable) of ≥ 1.5 or \>3 months respectively. 7. Any solid primary tumour. Lymphoma, germ cell tumor, small cell lung carcinoma and multiple myeloma are excluded. 8. Ability to provide written informed consent and to participate in the procedure of the questionnaires. Exclusion Criteria: 1. BM not amenable to SRT 2. Previous SRT or surgery on the same lesion 3. Co-morbidities considered clinically precluding the safe use of an MRI examination or SRT 4. Any psychological, sociological or geographical issue potentially hampering compliance with the study 5. Pregnancy 6. Concurrent use of systemic therapy 7. More than 10 BM on planning-MRI 8. Maximum cumulative GTV (+CTV for cavity) of more than 30cm3 on planning-MRI 9. A brainstem metastasis with a PTV of more than 20 cm3 10. Leptomeningeal disease