Recent Developments of Radiopharmaceuticals for Neuroendocrine Tumor Imaging and Therapy

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.

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111Indium Octreotide SPECT/CT for Neuroendocrine Tumor Imaging

Hybrid SPECT/CT Imaging in Clinical Practice ◽

10.3109/9781420016468-8 ◽

2016 ◽

pp. 93-108

Keyword(s):

Neuroendocrine Tumor ◽

Tumor Imaging

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The Glucose-Dependent Insulinotropic Polypeptide Receptor: A Novel Target for Neuroendocrine Tumor Imaging--First Preclinical Studies

Journal of Nuclear Medicine ◽

10.2967/jnumed.113.133744 ◽

2014 ◽

Vol 55 (6) ◽

pp. 976-982 ◽

Cited By ~ 15

Author(s):

E. Gourni ◽

B. Waser ◽

P. Clerc ◽

D. Fourmy ◽

J. C. Reubi ◽

...

Keyword(s):

Neuroendocrine Tumor ◽

Tumor Imaging ◽

Preclinical Studies ◽

Novel Target

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6-[18F]Fluoro-L-DOPA: A Well-Established Neurotracer with Expanding Application Spectrum and Strongly Improved Radiosyntheses

BioMed Research International ◽

10.1155/2014/674063 ◽

2014 ◽

Vol 2014 ◽

pp. 1-12 ◽

Cited By ~ 30

Author(s):

M. Pretze ◽

C. Wängler ◽

B. Wängler

Keyword(s):

Tumor Imaging ◽

Reaction Times ◽

Malignant Diseases ◽

Neuropsychiatric Diseases ◽

Recent Developments ◽

Specific Activities ◽

Radiochemical Yields ◽

Very High ◽

No Carrier Added

For many years, the main application of [18F]F-DOPA has been the PET imaging of neuropsychiatric diseases, movement disorders, and brain malignancies. Recent findings however point to very favorable results of this tracer for the imaging of other malignant diseases such as neuroendocrine tumors, pheochromocytoma, and pancreatic adenocarcinoma expanding its application spectrum. With the application of this tracer in neuroendocrine tumor imaging, improved radiosyntheses have been developed. Among these, the no-carrier-added nucleophilic introduction of fluorine-18, especially, has gained increasing attention as it gives [18F]F-DOPA in higher specific activities and shorter reaction times by less intricate synthesis protocols. The nucleophilic syntheses which were developed recently are able to provide [18F]F-DOPA by automated syntheses in very high specific activities, radiochemical yields, and enantiomeric purities. This review summarizes the developments in the field of [18F]F-DOPA syntheses using electrophilic synthesis pathways as well as recent developments of nucleophilic syntheses of [18F]F-DOPA and compares the different synthesis strategies regarding the accessibility and applicability of the products for humanin vivoPET tumor imaging.

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