Methods developed in the Laboratory of Nuclear Problems, JINR, for producing astatine-211 and injecting it into monoclonal antibodies are described. The use of its diethylene triamine penta-acetic acid complex is shown to be the most effective method of injecting astatine into a biomolecule.
The biological effect of the a-particles emitted from the astatine-211 is investigated using Chinese hamster fibroplasts and Ehrlich carcinoma cells. It is established that the mitotic activity depression, number of degenerating cells, number of cells with chromosome aberrations, and cellular surviving fraction depend on the concentration of the radionuclide in the medium in vitro. The RBE of a-particles in comparison with ⁶⁰Co g-rays is 3. Injection of astatine-211 absorbed on tellurium particles into mice with ascitic tumours resulted in prolongation of their life or elimination of the tumours.