introduction: radioimmunotherapy (rit) is a very promising new therapy for the treatment of recurrent b-cell non-hodgkin's lymphoma (nhl). iodine-131 is the most frequently used nuclide in clinical rit, but its usefulness has been limited by dehalogenation of monoclonal antibodies labeled via conventional methods. to circumvent this problem, we have synthesized a tri-peptide consisting of non-m...