Nuclear medicine covers the area of a medical practice based on injected radioactive substances, called radiopharmaceuticals, which can be applied for diagnosis (radiodiagnostics) or therapy (radiotherapeutics), or both (radiotheranostics).
The radiolabeled product, a substance containing a radioactive isotope or radionuclide, travels through the body up to reaching its target. Thanks to a vector, on which this radionuclide is grafted, it reaches and accumulates in a specific biological tissue or an organ. This molecule is then useful to locate the targeted tissue or organ (diagnosis), to initiate the destruction of these cells (therapy), or both depending upon the type of attached radionuclide.
The term radiotracer refers to the notion of minute (trace) amounts of the substances in use, and also to the advantageous ability to “trace” the dissemination of the molecule in the body as a consequence of the linked radioactivity (light). The development of imaging acquisition technology associated with powerful information technology software has resulted in the development of the tomography technology, generating cross sectional images and tri-dimensional pictures.
Some radioactive elements can be used for therapeutic purposes thanks to their different physico-chemical properties; indeed, their short distance ionizing effect leads to cell destruction. The use of these vectors in association with therapy radionuclides, essentially β or α emitters, is called vectorized or metabolic radiotherapy. Such radiolabeled drugs used in therapy are also called radiotherapeutics.
