This relatively new use of radiation involves the use of manufactured antibodies directed against very specific targets on the surface of cancer cells. These antibodies are injected intravenously and seek out certain types of cancer cells in tumors such as lymphomas.

By attaching a radioactive particle to the back end of these antibodies, we can locally irradiate the cancer at the cellular level, administering lethal doses to the tumor cells while sparing the majority of the surrounding normal tissues. These agents literally hunt down the cancer in the body cell by cell.