 3. Disease Evaluation: The patient must have a stable clinical neurologic in case of brain tumors exam and be on a stable dose of steroids for at least 1 week prior to study entry. The patient should have a measurable disease which is defined as the presence of at least one lesion that can be accurately measured in two dimensions each measures at least 10 mm or evaluable disease which is defined as at least one lesion that can be accurately measured in at least one dimension measure at least 10 mm. 