NCIt definition : A radioconjugate consisting of the somatostatin analogue tyrosine-3-octreotate (Tyr3-octreotate
or TATE) labeled with the positron emission tomography (PET) tracer gallium Ga 68
via the macrocyclic chelating agent dodecanetetraacetic acid (DOTA), which may be
used as a somatostatin receptor (SSTR) imaging agent in conjunction with PET to image
neuroendocrine tumors (NETs). Gallium Ga 68-DOTATATE binds to SSTRs, with a much higher
affinity for type 2 SSTR, present on the cell membranes of many types of NETs. This
allows for visualization of SSTR-positive cells upon imaging. SSTR subtypes have been
shown to be present in large numbers on NETs and their metastases, while most other
normal tissues express low levels of SSTR subtypes.;