Nuclear Medicine Theranostics: Between Atoms and Patients

In the last two decades, the demand for a personalized therapeutic approach has been constantly increasing, mainly due to the need to develop ever more effective therapeutic regimens, to improve outcome, and to avoid unnecessary treatments. Theranostics is an invaluable tool in personalized medicine; it is a treatment strategy in which the same (or very similar) agents are used for both diagnostic and therapeutic purposes. Particularly, theranostics is based on the integration of a diagnostic test and a specific treatment and it relies on the idea of selecting patients through a diagnostic study that could detect whether a patient will benefit from a certain therapy or not. After a brief historical review a critical update on theranostics will be provided in this chapter.