Document Detail


Exendin-4-based radiopharmaceuticals for glucagonlike peptide-1 receptor PET/CT and SPECT/CT.
MedLine Citation:
PMID:  20595511     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Strong overexpression of glucagonlike peptide-1 (GLP-1) receptors in human insulinoma provides an attractive target for imaging. The first clinical trials demonstrated that GLP-1 receptor SPECT/CT using [Lys(40)(Ahx [6-aminohexanoic acid]-DOTA-(111)In)NH(2)]-exendin-4 can localize hardly detectable insulinomas. However, [Lys(40)(Ahx-DOTA-(111)In)NH(2)]-exendin-4 imaging has drawbacks related to the use of (111)In in that it is costly and carries a relatively high radiation burden for the patient. The aim of this study was the preclinical evaluation of [Lys(40)(Ahx-DOTA-(68)Ga)NH(2)]-exendin-4 for PET/CT and [Lys(40)(Ahx-hydrazinonicotinamide [HYNIC]-(99m)Tc)NH(2)]-exendin-4 for SPECT/CT. METHODS: Internalization, biodistribution, dosimetry, and imaging studies were performed in the Rip1Tag2 mouse model of pancreatic beta-cell carcinogenesis and compared with our gold standard [Lys(40)(Ahx-DOTA-(111)In)NH(2)]-exendin-4. Poly-glutamic acid and Gelofusine, a gelatin-based plasma expander, were used for renal uptake reduction studies. RESULTS: The tumor uptake of [Lys(40)(Ahx-DOTA-(68)Ga)NH(2)]-exendin-4 was 205 +/- 59 percentage injected activity per gram of tissue at 4 h. Other GLP-1 receptor-positive organs showed more than 4.8 times lower radioactivity uptake. [Lys(40)(Ahx-HYNIC-(99m)Tc/ethylenediaminediacetic acid [EDDA])NH(2)]-exendin-4, compared with its (111)In- and (68)Ga-labeled sister compounds, showed significantly less tumor and organ uptake. The significantly lower tumor and organ uptake of [Lys(40)(Ahx-HYNIC-(99m)Tc/EDDA)NH(2)]-exendin-4 did not result in inferior tumor-to-organ ratios or reduced image quality. All radiopeptides tested showed a high tumor-to-background ratio, resulting in the visualization of small tumors (maximum diameter between 1.0 and 3.2 mm) by SPECT and PET. The only exception was the kidneys, which also showed high uptake. This uptake could be reduced by 49%-78% using poly-glutamic acid, Gelofusine, or a combination of the 2. The estimated effective radiation dose was 3.7 muSv/MBq for [Lys(40)(Ahx-HYNIC-(99m)Tc/EDDA)NH(2)]-exendin-4, which was 8 times less than that for [Lys(40)(Ahx-DOTA-(68)Ga)NH(2)]-exendin-4 and 43 times less than that for [Lys(40)(Ahx-DOTA-(111)In)NH(2)]-exendin-4. CONCLUSION: These promising pharmacokinetic and imaging data show that [Lys(40)(Ahx-DOTA-(68)Ga)NH(2)]-exendin-4 and [Lys(40)(Ahx-HYNIC-(99m)Tc/EDDA)NH(2)]-exendin-4 are suitable candidates for clinical GLP-1 receptor imaging studies.
Authors:
Damian Wild; Andreas Wicki; Rosalba Mansi; Martin Béhé; Boris Keil; Peter Bernhardt; Gerhard Christofori; Peter J Ell; Helmut R Mäcke
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of nuclear medicine : official publication, Society of Nuclear Medicine     Volume:  51     ISSN:  1535-5667     ISO Abbreviation:  J. Nucl. Med.     Publication Date:  2010 Jul 
Date Detail:
Created Date:  2010-07-02     Completed Date:  2010-07-27     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0217410     Medline TA:  J Nucl Med     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1059-67     Citation Subset:  IM    
Affiliation:
Clinic and Institute of Nuclear Medicine, University Hospital Basel, Basel, Switzerland.
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MeSH Terms
Descriptor/Qualifier:
Animals
Cells, Cultured
Dose-Response Relationship, Radiation
Female
Gallium Radioisotopes / diagnostic use
Indicators and Reagents
Indium Radioisotopes / diagnostic use
Isotope Labeling
Kidney / metabolism,  radionuclide imaging
Male
Mice
Mice, Transgenic
Peptides / chemistry,  diagnostic use*
Positron-Emission Tomography
Radiopharmaceuticals / chemistry,  diagnostic use*
Receptors, Glucagon / metabolism*
Technetium Compounds / diagnostic use
Tissue Distribution
Tomography, Emission-Computed
Tomography, Emission-Computed, Single-Photon
Venoms / chemistry,  diagnostic use*
Chemical
Reg. No./Substance:
0/Gallium Radioisotopes; 0/Indicators and Reagents; 0/Indium Radioisotopes; 0/Peptides; 0/Radiopharmaceuticals; 0/Receptors, Glucagon; 0/Technetium Compounds; 0/Venoms; 0/glucagon-like peptide receptor; 141732-76-5/exenatide

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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