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 (131I/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 specificity (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.
Recent Developments of Radiopharmaceuticals for Neuroendocrine Tumor Imaging and Therapy
