In this study, we evaluated whether 213Bi-[DOTA0, Tyr3]-octreotate (213Bi-DOTATATE), a 213Bi-labelled somatostatin analogue with high affinity for somatostatin receptor subtype 2 (SSTR2), is suitable for the treatment of larger neuroendocrine tumours overexpressing SSTR2 in comparison to its effectiveness for smaller tumours. Here, SSTR2 is linked to neuroendocrine neoplasm.