Radioisotopes are extensively used in nuclear medicine to explore body structures and functions in vivo (in the living body) with a minimum of invasion to the organ or treatment site. Radioisotopes, containing unstable combinations of protons and neutrons. Radioisotopes are also used in radiotherapy (radiation therapy) to treat some cancers and other medical conditions that require destruction of harmful cells.
Radioisotopes allow high quality imaging of bones, soft organs and a number of diagnostic techniques in nuclear medicine use gamma ray emitting tracers. The tracers are formed from the bonding of short-lived radioisotopes with chemical compounds that allow the targeting of specific body regions or physiologic processes. Radioisotope most widely used in medicine is technetium-99m. Radioisotopes can be manufactured in several ways; most common is by neutron activation in a nuclear reactor.