What is Radioimmunotherapy?

Radioimmunotherapy is a cancer treatment approach that combines a form of immunotherapy, monoclonal antibodies, and radioactive isotopes, in order to use the immune system to deliver radioactive particles directly to cancer cells by targeting them on a molecular level.
Radioimmunotherapy involves attaching a radioactive isotope, such as Lutetium 177, to a cancer-targeting antibody or small molecule that binds only to a specific cancer-related molecule on a tumor cell.
This is similar to a “lock and key” scenario, where the antibody or molecule serves as a key that will only recognize a very specific lock (the cancer-related molecule).
In prostate cancer, nearly all cells have a specific “lock” that lives on the surface of each cell called prostate-specific membrane antigen (PSMA).