Octreotide(Peptron, Inc.)

Here, we report on the first patient (78-yr-old man) with a metastatic, hormone-active (carcinoid syndrome) ileal neuroendocrine tumor (G1, Ki-67, < 3%), who received a test infusion of 1 GBq [¹⁶¹Tb]Tb-DOTA-LM3 in an ongoing prospective Phase 0 study.So far, the patient received long-acting octreotide, which was stopped 2 mo before [¹⁶¹Tb]Tb-DOTA-LM3 infusion.The ¹⁶¹Tb emits conversion electrons and high quantities of Auger electrons (1213%) with a high linear energy transfer over a short distance (< 40 keV/μm), while Somatostatin receptor subtype 2 antagonists such as DOTA-LM3 bind to many more binding sites, which leads to a much higher tumor accumulation compared to somatostatin receptor subtype 2 agonists.The case presented shows the potential of [¹⁶¹Tb] Tb-DOTA-LM3 as a promising alternative to the current standard peptide receptor radionuclide therapy with [¹⁷⁷Lu]Lu-DOTATOC/[ ¹⁷⁷Lu]Lu-DOTATATE (Lutathera) for patients with metastatic gastroenteropancreatic neuroendocrine tumors.