Recent developments in molecular biology, proteomics and genetics have significantly enriched understanding of tumor biochemistry and function, including identification of the receptors tumor cells express. In theranostics, these molecular targets can be used to access tumors, image the disease area and deliver targeted cytotoxic substances directly to tumor tissue.
In position emission tomography (PET) and single-photon emission computed tomography (SPECT) imaging applications, molecular targets can be combined with radiotracers for both diagnostic and therapeutic purposes. Diagnostic imaging is performed to determine tumor size, classification and stage so that localized radiation can be administered specifically to the diseased area, without damaging any surrounding healthy cells.