 Because electrochemotherapy is a quick and effective treatment for cutaneous metastases, a novel electrode device has been developed for treatment in soft tissue such as the brain. Up to 18 patients will be treated in this phase I dose-escalating study of electrochemotherapy for brain metastases. Primary endpoint of the clinical trial is safety and secondary endpoint is efficacy. One brain metastasis is treated once-only with the electrode device guided stereotactically through a burr hole using CT monitoring. The patient will be fully anesthetized during the treatment procedure. Patients are followed up for 6 months with regard to neurological function, Barthel Index, steroid use and adverse effects registration CTCAE. Tumor response will be evaluated by Magnetic Resonance imaging MRI. 