In this feasibility study, [18F]dabrafenib will be used as radioactive tracer. All patients in this study are diagnosed with advanced melanoma with evidence of brain metastases and are eligible for treatment with dabrafenib, a specific V600-mutated BRAF inhibitor. Patients will undergo a dynamic PET scan of the brain to determine [18F]dabrafenib distribution and kinetics in brain metastases. In addition, a static total body PET scan will be performed to visualize whole body distribution and tracer uptake.