POTENTIAL FUTURE APPLICATION WITH THERAPEUTIC AGENTS

Several new approaches to radiation therapy with radionuclides have been discussed. Iron 55 is selectively utilized in the red cell developmental cycle and in therapeutic doses, can lower marrow and circulating erythrocyte levels with much smaller degrees of effect on other cell lines. A serious complication, noted in animal studies, is the induction of neoplasma, especially osteosarcoma. Selective irradiation of the cell nucleus is possible with 125IUdR. This results in highly efficient cell killing due to the highly concentrated region of ionization. High concentrations of densely ionizing radiation in the malignant cell may also be accomplished with 211At. The use of labeled liposomes is an additional approach to the delivery of intracellular irradiation. None of these approaches is applicable for the practical treatment of human malignancy at the present time. The importance of these approaches is their value as models for future development of methods that can provide highly selective radiation to target sites. © 1979 Grune & Stratton, Inc.