Study of Radiolabeled Monoclonal Antibody Anti-B1 for the Treatment of B-Cell Lymphomas and Extended Study to Determine the Safety and Efficacy of Coulter Clone® 131Iodine-B1 Radioimmunotherapy of Advanced Non-Hodgkin's Lymphoma

131-I anti-B1 is the product of 131-I labeling of the anti-CD20 murine monoclonal antibody and the anti-B1 antibody itself is an intact IgG2a murine monoclonal antibody which has specificity far the CD20 antigen on human B cells. Anti-B1 is a clear, colorless liquid. 131-I labeling of the anti-B1 antibody will be carried out by iodogen technique. Trace labeling of the antibody will involve the labeling of approximately 1 to 3 mg of antibody with 5 mCi of 131-I.