Radiopharmacology
Radiopharmacology is the application of radiochemistry to medicine, and thus the Pharmacology of radiopharmaceuticals (medicinal radio compounds, that is, pharmaceutical drugs that are radioactive). Radiopharmaceuticals are used as radioactive tracers in medical imaging and therapy for a variety of diseases in the field of nuclear medicine (for example, brachytherapy). Many radiopharmaceuticals employ technetium-99m (Tc-99m), a gamma-emitting tracer nuclide with numerous applications. There are 31 different radiopharmaceuticals based on Tc-99m listed in the book Technetium for imaging and functional studies of the brain, myocardium, thyroid, lungs, liver, gallbladder, kidneys, skeleton, blood, and tumours. The term radioisotope, which refers to any radioactive isotope (radionuclide) in its broadest sense, has historically been used to refer to all radiopharmaceuticals, and this usage persists.