Study of Immunotoxin, MR1-1

Inclusion Criteria: - Residual, progressive, or recurrent supratentorial malignant brain tumor based on imaging studies with measurable disease (>0.5cm). - Patient will have completed some form of radiation therapy prior to toxin treatment. - Karnofsky Performance score >70. - The presence of the target antigen, EGFRvIII, must be identified on tumor tissue by immunohistochemistry. - Platelet count > 100 x 109/L; PTT and PT < 120% of normal range. - Creatinine < 120% of normal range. - Total bilirubin, SGOT, SGPT,alkaline phosphatase < 300% of normal range. Exclusion Criteria: - Patients who are pregnant, breast-feeding, or unwilling to practice an effective method of birth control. - Patients with known potentially anaphylactic allergic reactions to iodine or gadolinium-DTPA. - Patients who cannot undergo MRI due to obesity or to having certain metal in their bodies (specifically pacemakers, infusion pumps, metal aneurysm clips, metal prostheses, joints, rods or plates). - Patients that have not recovered from the toxic effects of prior chemotherapy and/or radiation therapy. - Patients with an impending, life-threatening cerebral herniation syndrome. - Patients with subependymal or CSF disease. - Patients who are under the age of 18 years.