PSMA studies are performed on newly diagnosed prostate cancer patients to determine if the disease has spread to pelvic lymph nodes. The study is also performed on patients who have had their prostate gland removed (prostatectomy) and have an increase in prostate-specific antigen (PSA) blood levels.
The study involves a special molecule called a monoclonal antibody developed in a laboratory and designed to bind to the prostate-specific membrane antigen on cancer cells. This antibody is paired with a radioactive material called Indium-111that can be detected by a gamma camera. When injected into the patient’s bloodstream, the radioactive antibody, called a radiotracer, travels and attaches to prostate cancer cells. The gamma camera then produces three-dimensional images of the tumor and its location inside the body.
This study is performed over as many as three days. On the first day, the patient first receives an intravenous (IV) injection of the radioactive antibody. Imaging is performed in two sessions, separated by 24 or more hours. Each imaging session lasts about two hours.