Theranostics represents a concept in personalized medicine wherein the same or similar targeting molecules are used both for diagnostics and therapeutics.
In oncology, theranostics has acquired greater importance in recent years, as advanced, hard-to-treat tumors have been effectively treated with low side effects (Langbein T et al., 2019). Some of the most prominent examples are drugs termed radiopharmaceuticals, which are usually employed as theranostic pairs. Radiopharmaceuticals are based on small molecule compounds or antibodies that target cell surface receptors overexpressed on tumor cells. A theranostic pair describes two similar drugs based on the same targeting molecule but containing different effector compounds, e.g., two different radioisotopes, for diagnosis and therapy.
A radiopharmaceutical consists of a tumor-targeting molecule combined with a diagnostic or therapeutic radioisotope via a chelator. These are then referred to as radiodiagnostic and radiotherapeutic agents. The great strength of the theranostics paradigm is the precise selection of patients, at the imaging stage, who will potentially benefit from the targeted radionuclide therapy (Turner JH 2018).
Take a look at the components of a typical radiopharmaceutical. Watch this video to learn more about their mode of action.