In steps. Radio-immunotherapy (rit) is given in three steps, all through an iv. Step 1: an antibody to b cells alone to clear out some normal b cells. Step 2: an antibody to b cells with a small amount of radiation attached, followed by imaging. Step 3: a "hot" antibody to b cells with a larger dose of radiation attached. This acts like a smart bomb to kill cancerous b cells (lymphoma cells).
Radioimmunotherapy. Radioimmunotherapy (rit) uses an antibody labeled with a radionuclide to deliver cytotoxic radiation to a target cell. In cancer therapy, an antibody with specificity for a tumor-associated antigen is used to deliver a lethal dose of radiation to the tumor cells. The ability for the antibody to specifically bind to a tumor-associated antigen increases the dose delivered to the tumor cells.