DOTA-TATE is a compound containing tyrosine3-octreotate,[2] an SSR agonist, and the bifunctional chelatorDOTA (tetraxetan).[5][6] SSRs are found with high density in numerous malignancies, including CNS, breast, lung, and lymphatics.[7] The role of SSR agonists (i.e. somatostatin and its analogs such as octreotide, somatuline and vapreotide) in neuroendocrine tumours (NETs) is well established,[8] and massive SSR overexpression is present in several NETs. (Tyr3)-octreotate binds the transmembrane receptors of NETs with highest activity for SSR2 and is actively transported into the cell via endocytosis, allowing trapping of the radioactivity and increasing the probability of the desired double-strand DNA breakage (for tumour control). Trapping improves the probability of this kind of effect due to the relatively short range of the beta particles emitted by 177Lu, which have a maximum range in tissue of <2 mm.[9][8][10]Bystander effects include cellular damage by free radical formation.
68Ga DOTA-TATE (gallium-68 dotatate, GaTate) is used to measure tumor SSR density and whole-body bio-distribution via PET imaging.[11][12]68Ga DOTA-TATE imagery has a much higher sensitivity and resolution compared to 111In octreotide gamma camera or SPECT scans, due to intrinsic modality differences.[11] It is commonly used to confirm the presence of paragangliomas and pheochromocytomas.[13]
Copper-64 DOTA-TATE
Copper (64Cu) oxodotreotide or copper Cu 64 dotatate, sold under the brand name Detectnet, is a radioactive diagnostic agent indicated for use with positron emission tomography (PET) for localization of somatostatin receptor positiveneuroendocrine tumors (NETs) in adults. It was FDA approved in September 2020. These are the same indications for as the gallium DOTA-TATE scans, but Cu-64 has advantages over Ga-68 in having a 12-hour half life rather than the much shorter one-hour half life of Ga-68, making it easier to transport from central production locations. [14][15]
Alternatives to 177Lu-DOTA-TATE include 90Y (T1/2 = 64.6 h) DOTA-TATE. The longer penetration range in the target tissues of the more energetic beta particles emitted by 90Y (high average beta energy of 0.9336 MeV) could make it more suitable for large tumors while 177Lu would be preferred for smaller volume tumors.[18][19]
^Reubi JC, Laissue JA (March 1995). "Multiple actions of somatostatin in neoplastic disease". Trends in Pharmacological Sciences. 16 (3): 110–5. doi:10.1016/S0165-6147(00)88992-0. PMID7792931.
^ abMazziotti G, Mosca A, Frara S, Vitale G, Giustina A (November 2017). "Somatostatin analogs in the treatment of neuroendocrine tumors: current and emerging aspects". Expert Opinion on Pharmacotherapy. 18 (16): 1679–1689. doi:10.1080/14656566.2017.1391217. PMID29067877. S2CID46747267.
^Breeman WA, de Blois E, Sze Chan H, Konijnenberg M, Kwekkeboom DJ, Krenning EP (July 2011). "(68)Ga-labeled DOTA-peptides and (68)Ga-labeled radiopharmaceuticals for positron emission tomography: current status of research, clinical applications, and future perspectives". Seminars in Nuclear Medicine. 41 (4): 314–321. doi:10.1053/j.semnuclmed.2011.02.001. PMID21624565.
^"FDA approval letter"(PDF). 3 September 2020. Retrieved 5 September 2020. This article incorporates text from this source, which is in the public domain.