Nuclear Africa, Kelvin Kemm: What is nuclear medicine? Nuclear medicine involves the application of radioactive substances to people, in both the diagnosis and the treatment of disease. In nuclear medicine procedures, radioisotopes are combined with other chemicals or pharmaceutical compounds to form radiopharmaceuticals. They migrate through the body and localise in specific organs or cellular receptors. This property provides nuclear medicine with the ability to image the extent of a disease process in the body, based on the cellular function and physiology, rather than relying only on physical changes in the tissue anatomy.