Definition

A radioconjugate consisting of the tyrosine-containing somatostatin analog Tyr3-octreotate (TATE) conjugated, through a bifunctional, macrocyclic chelating agent DOTAM (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic amide; TCMC), to the alpha-emitting radioisotope lead Pb 212, with potential antineoplastic activity. Upon administration, lead Pb 212 DOTAMTATE targets and binds to somatostatin receptors (SSTRs) present on the cell membranes of most types of neuroendocrine tumor (NET) cells. This allows for the specific delivery of a cytotoxic dose of alpha radiation to SSTR-positive cells. TATE is an octreotide derivative in which phenylalanine at position 3 is substituted by tyrosine and position 8 threoninol is replaced with threonine. SSTRs have been shown to be present in large numbers on NET and their metastases, while most other normal tissues express low levels of SSTRs.