Figure 1.

The general concept of theranostic radiopharmaceuticals. A radionuclide is combined with a targeting vector (Binding molecule). The choice of radionuclide defines the purpose of the radiopharmaceutical. γ⁻ or β⁺-emitters are used for diagnostics while β⁻- and α-emitters are applied in therapy. The targeting vector guides the radiopharmaceutical to its specific target (e.g., receptors). To combine the radionuclide with a target vector without reducing its affinity to its target, normally, depending on the type of radionuclide (e.g., metal, non-metal), linking structures (linker molecules) are necessary.