CCKBR and medullary thyroid gland carcinoma: The promising data of this preliminary study, which reflects the high therapeutic potential of CCK-2R directed 177Lu-RLT and 225Ac-TAT, should encourage future comparative preclinical evaluation of our novel compounds [177Lu]Lu-DOTA-CCK-66 and [225Ac]Ac-DOTA-CCK-66 in regard to biodistribution, dosimetry, dose-dependant response and long term-toxicity studies, to further pave the way for first in-human clinical applications in MTC patients.