A new 68Ga-labeled somatostatin analog containing two iodo-amino acids for dual somatostatin receptor subtype 2 and 5 targeting.

[68Ga]Ga-DOTA-ST8950 reveals its potential for PET imaging SST2- and SST5-expressing tumors. It compares favorably with the clinically used [68Ga]Ga-DOTA-NOC in terms of tumor uptake; however, its uptake in the liver remains a challenge for clinical translation. In addition, this study reveals the essential role of the iodo-substitutions in positions 1 and 3 of [68Ga]Ga-DOTA-ST8950 for maintaining affinity to SST2 and SST5, as the de-iodinated [68Ga]Ga-DOTA-ST8951 lost affinity for both receptor subtypes.