Radionuclide
A radioactive atom that emits radiation. In nuclear medicine, radionuclides are used for diagnosis or therapy. Well-known examples include lutetium-177, actinium-225, and lead-212.

Radiopharmaceutical
A drug that contains a radionuclide. The radionuclide is linked to a molecule that targets a specific tissue or organ, such as tumor cells.
Nuclear medicines Medicines that use radioactive substances for diagnosis or treatment. In scientific literature, the term radionuclide therapy is also often used as a collective term for these. Radiopharmaceuticals are a type of nuclear medicine.

TRT (Targeted Radionuclide Therapy) 
A form of treatment in which a radionuclide is delivered specifically to diseased tissue, such as a tumor, via a targeting molecule; Pluvicto (lutetium-177-PSMA) is a well-known example. The term radioligand therapy is also often used to describe this type of therapy (RLT, radioligand therapy). In addition to TRT or RLT, terms are sometimes used that also describe the targeting molecule; this is the case, for example, with Peptide Receptor Radionuclide Therapy (PRRT). TRT is the term used in the Dutch strategic research agenda and encompasses all forms of targeted radionuclide therapy.

Theranostics
The combination of diagnostics and therapy using the same molecule, labeled with different radionuclides. The diagnostic radionuclide enables imaging and reveals whether the tumor expresses the target. The therapeutic radionuclide then specifically targets and treats that same tumor. This enables personalized treatment and targeted patient selection.

Dosimetry
The measurement and calculation of the radiation dose a patient receives during treatment with a radionuclide. Accurate dosimetry enables personalized treatment and minimizes side effects.