Nuclear medicine is a medical specialty that uses ionizing radiation from radioisotopes or radionuclides to perform morphological and functional studies of many different organs and to carry out radioanalytical determinations of a broad range of substances in the body.

Although nuclear medicine is fundamentally a diagnostic specialty, it also encompasses all the applications based on the use of radionuclides for therapeutic purposes. In this regard, two major areas of nuclear medicine may be distinguished:

  • Nuclear molecular diagnosis
  • Nuclear molecular therapy

These studies and therapies require the administration of trace amounts of a radiopharmaceutical – a specific, radioactively-labelled molecule.

It can be administered via different routes – fundamentally intravenously, though the oral or inhalatory routes can also be used. As a result of their special affinity, radiopharmaceuticals are distributed in the body and are taken up by the organ being studied or treated. Since these drugs emit radiation, images can be obtained for the target zone or the latter can be treated, depending on the purpose and the objective of the test.