Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P61278 (somatostatin)
 22,083 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Neuroendocrine tumors (NET) are a heterogeneous group of tumors that arise from neuroendocrine cells. These tumors may arise from various organs, including lung, thymus, thyroid, stomach, duodenum, small bowel, large bowel, appendix, pancreas, adrenal, and skin. Most are well differentiated and have the ability to produce biogenic amines and various hormones. NET usually occur sporadically but they also be associated with various familial syndromes. For the vast majority of NET, surgical resection is the treatment of choice whenever feasible. Localization of NET prior to surgery and for staging and follow-up relies on both anatomic and functional imaging modalities. In fact, the unique secretory characteristics of these tumors lend themselves to imaging by molecular imaging modalities, which can target specific metabolic pathways or receptors. Neuroendocrine cells have a variety of such target receptors and pathways for which radiopharmaceuticals have been developed, including [(123)I/(131)I]-metaiodobenzylguanidine (MIBG), [(111)In]pentetreotide, [(68)Ga] somatostatin analogs, [(18)F] fluorodeoxyglucose (FDG), [(11)C/(18)F] dihydroxyphenylalanine (DOPA), [(11)C] 5-hydroxytryptophan (5-HTP) (99m)Tc pentavalent dimercaptosuccinic acid ([(99m)Tc] (V) DMSA, and [(18)F] fluorodopamine (FDA). Here, we review the molecular imaging approaches for NET using various radiopharmaceuticals.
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PMID:Molecular imaging of neuroendocrine tumors. 2116 84

The new positron emission tomography (PET/CT) methods for neuroendocrine tumors detection are presented and compared with classic, conventional methods. Conventional methods use a gamma scintillation camera for patients with neuroendocrine tumor imaging, after intravenous injection of one of the following radiopharmaceuticals: 1) somatostatin analogues labeled with indium-111 (111In-pentetreotide) or technetium-99m (99mTc-EDDA/HYNIC-TOC); 2) noradrenaline analogue labeled with iodine-131 or -123 (131/123I-MIBG); or 3) 99mTc(V)-DMSA. Contemporary methods use PET/CT equipment for patients with neuroendocrine tumor imaging, after intravenous injection of pharmaceuticals labeled with positron emitters [fluorine-18 (18F), galium-68 (68Ga), or carbon-11 (11C)]: 1) glucose analogue (18FDG); 2) somatostatin analogue (68Ga-DOTATOC/68Ga-DOTATATE/68Ga-DOTANOC); 3) aminoacid precursors of bioamines: [a) dopamine precursor 18F-DOPA (6-18F-dihydroxyphenylalanine), b) serotonin precursor 11C-5HTP (11C-5-hydroxytryptophan)]; or 4) dopamine analogue 18F-DA (6-18F-fluorodopamine). Conventional and contemporary (PET/ CT) somatostatin receptor detection showed identical high spe- cificity (92%), but conventional had very low sensitivity (52%) compared to PET/CT (97%). It means that almost every second neuroendocrine tumor detected by contemporary method cannot be discovered using conventional (classic) method. In metastatic pheochromocytoma detection contemporary (PET/ CT) methods (18F-DOPA and 18F-DA) have higher sensitivity than conventional (131I/123I-MIBG). In medullary thyroid carcinoma diagnostics contemporary method ([18F-DOPA) is more sensitive than conventional 99mTc(V)-DMSA method, and is similar to 18FDG, computed tomography and magnetic resonance. In carcinoid detection contemporary method (18F-DOPA) shows similar results with contemporary somatostatin receptor detection, while for gastroenteropancreatic neuroendocrine tumors it is worse. To conclude, contemporary (PET/CT) methods for somatostatin receptor detection (68Ga-DOTATOC/-NOC/-TATE) in neuroendocrine tumors are much more sensitive (almost twice) and more accurate than conventional. Therefore the classical methods should be urgently replaced by contemporary methods.
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PMID:[Contemporary nuclear medicine diagnostics of neuroendocrine tumors]. 2584 63


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