Fig. 5

Chemical structures of clinically evaluated tumour-direct FAP, PSMA, and SSTR targeting radiopharmaceuticals. Representative clinically evaluated tumour-directed FAP-, PSMA- and SSTR-targeting radiopharmaceuticals. PSMA-targeting radiopharmaceuticals with a glutamate-urea-lysine structural motif, including PSMA-11, PSMA-1007, PSMA-617, and rhPSMA-7.3, have been approved. PSMA-targeting ligands that enable simultaneous diagnosis and therapy, including PSMA-I&T and rhPSMA, are of high value. SSTR-targeting radiopharmaceuticals play essential roles in the radiotheranostics of NETs. The antagonists, including LM3 and JR11, which have greater safety and affinity, are promising in SSTR-targeting imaging agents. FAP-targeting radiotracers may prove advantageous over [¹⁸F]FDG in the localization and visualization of solid tumours, such as FAPI-04, FAPI-46, and FAPI-74. Additionally, FAP-2286 has been shown to facilitate radiotheranostics. Grey circles: natural amino acids; blue circles: unnatural amino acids; highlighting in red: labelling with fluorine-18; highlighting in purple: chelators for metal radionuclide labelling