Inclusion Criteria:  Primitive cancer (brest cancer, lung cancer, melanoma) proven histologically Presence of brain metastasis visualized on MRI, of which at least one measures 5 mm Age > 18 years Patient has valid health insurance Written informed consent obtained from the patient prior to performing any protocol-related procedures, including screening evaluations  Exclusion Criteria:  History of irradiation cerebral History of brain surgery for brain metastasis or glial tumor Systemic therapy (chemotherapy, targeted therapy, immunotherapy) modified in the 6 weeks preceding the realization of DOPA PET/CT, New anti-tumor treatment started between the discovery of brain metastases and the performance of DOPA PET/CT Other concomitant cancer, or history of cancer in the 5 years preceding the performance of DOPA PET/CT Pregnant or lactating females Persons deprived of their liberty, under a measure of safeguard of justice, under guardianship or placed under the authority of a guardian.  Disorder precluding understanding of trial information or informed consent.