Radioimmunotherapy

Radioimmunotherapy (RIT) uses an antibody labeled with a radionuclide to deliver cytotoxic radiation to a target cell, and is a form of unsealed source radiotherapy. In cancer therapy, an antibody with specificity for a tumor-associated antigen delivers a lethal dose of radiation to tumor cells; because the antibody binds specifically to that antigen, the dose delivered to the tumor increases while the dose to normal tissue decreases. The technique requires the tumor cell to express an antigen that is unique to the tumor or otherwise inaccessible in normal cells.