Radiolabelled Monoclonal Antibodies - Radiolabelled monoclonal antibodies have also been developed  for delivery of a cytotoxic effector to target cells and for radioimaging. For therapy, one advantage of using radiolabelled antibodies, is that they can kill cells from a distance and thus can also kill cells adjacent to antigen expressing cells.

Further, the radiolabelled antibody need not be internalized to kill the tumour cells. For the purpose both β emitting .(e.g 731 I) and alpha emitting radionuclides. have been used for patients with hepatoma, HTL V-1 (human T cell leukemia/lymphoma virus -1), ATL (adult T-cell leukemia), a variety of allografts, etc.