- Patients may have had prior CNS metastasis providing, the patient's CNS disease has been previously treated, the patient's CNS disease has been clinically stable for four weeks prior to starting this study (assessment must be made clinically and by CT or MRI scan), and the patient is off steroids for CNS disease for four weeks prior to starting on study and during the course of the study. Patients with seizure disorders may be enrolled if on anti-convulsants and are well controlled.