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Gilpin IMF, Ullrich M, Wünsche T, Zarschler K, Lebeda O, Pietzsch J, Pietzsch H, Walther M. Radiolabelled Cyclic Bisarylmercury: High Chemical and in vivo Stability for Theranostics. ChemMedChem 2021; 16:2645-2649. [PMID: 33949125 PMCID: PMC8518081 DOI: 10.1002/cmdc.202100131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 04/26/2021] [Indexed: 11/28/2022]
Abstract
We show the synthesis of an in vivo stable mercury compound with functionality suitable for radiopharmaceuticals. The designed cyclic bisarylmercury was based on the water tolerance of organomercurials, higher bond dissociation energy of Hg-Ph to Hg-S, and the experimental evidence that acyclic structures suffer significant cleavage of one of the Hg-R bonds. The bispidine motif was chosen for its in vivo stability, chemical accessibility, and functionalization properties. Radionuclide production results in 197(m) HgCl2 (aq), so the desired mercury compound was formed via a water-tolerant organotin transmetallation. The Hg-bispidine compound showed high chemical stability in tests with an excess of sulfur-containing competitors and high in vivo stability, without any observable protein interaction by human serum assay, and good organ clearance demonstrated by biodistribution and SPECT studies in rats. In particular, no retention in the kidneys was observed, typical of unstable mercury compounds. The nat Hg analogue allowed full characterization by NMR and HRMS.
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Affiliation(s)
- Ian Moore F. Gilpin
- Institute of Radiopharmaceutical Cancer ResearchHelmholtz-Zentrum Dresden-RossendorfBautzner Landstrasse 40001328DresdenGermany
- Faculty of Chemistry and Food ChemistrySchool of ScienceDresden University of TechnologyMommsenstrasse 901062DresdenGermany
| | - Martin Ullrich
- Institute of Radiopharmaceutical Cancer ResearchHelmholtz-Zentrum Dresden-RossendorfBautzner Landstrasse 40001328DresdenGermany
| | - Thomas Wünsche
- Institute of Radiopharmaceutical Cancer ResearchHelmholtz-Zentrum Dresden-RossendorfBautzner Landstrasse 40001328DresdenGermany
| | - Kristof Zarschler
- Institute of Radiopharmaceutical Cancer ResearchHelmholtz-Zentrum Dresden-RossendorfBautzner Landstrasse 40001328DresdenGermany
| | - Ondřej Lebeda
- Department of RadiopharmaceuticalsNuclear Physics Institute of the CASŘež 130250 68Husinec-ŘežCzech Republic
| | - Jens Pietzsch
- Institute of Radiopharmaceutical Cancer ResearchHelmholtz-Zentrum Dresden-RossendorfBautzner Landstrasse 40001328DresdenGermany
- Faculty of Chemistry and Food ChemistrySchool of ScienceDresden University of TechnologyMommsenstrasse 901062DresdenGermany
| | - Hans‐Jürgen Pietzsch
- Institute of Radiopharmaceutical Cancer ResearchHelmholtz-Zentrum Dresden-RossendorfBautzner Landstrasse 40001328DresdenGermany
| | - Martin Walther
- Institute of Radiopharmaceutical Cancer ResearchHelmholtz-Zentrum Dresden-RossendorfBautzner Landstrasse 40001328DresdenGermany
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García-Varela L, Rodríguez-Pérez M, Custodia A, Moraga-Amaro R, Colabufo NA, Aguiar P, Sobrino T, Dierckx RA, van Waarde A, Elsinga PH, Luurtsema G. In Vivo Induction of P-Glycoprotein Function can be Measured with [ 18F]MC225 and PET. Mol Pharm 2021; 18:3073-3085. [PMID: 34228458 PMCID: PMC8383301 DOI: 10.1021/acs.molpharmaceut.1c00302] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 06/24/2021] [Accepted: 06/24/2021] [Indexed: 12/12/2022]
Abstract
P-Glycoprotein (P-gp) is an efflux pump located at the blood-brain barrier (BBB) that contributes to the protection of the central nervous system by transporting neurotoxic compounds out of the brain. A decline in P-gp function has been related to the pathogenesis of neurodegenerative diseases. P-gp inducers can increase the P-gp function and are considered as potential candidates for the treatment of such disorders. The P-gp inducer MC111 increased P-gp expression and function in SW480 human colon adenocarcinoma and colo-320 cells, respectively. Our study aims to evaluate the P-gp inducing effect of MC111 in the whole brain in vivo, using the P-gp tracer [18F]MC225 and positron emission tomography (PET). Eighteen Wistar rats were treated with either vehicle solution, 4.5 mg/kg of MC111 (low-dose group), or 6 mg/kg of MC111 (high-dose group). Animals underwent a 60 min dynamic PET scan with arterial-blood sampling, 24 h after treatment with the inducer. Data were analyzed using the 1-tissue-compartment model and metabolite-corrected plasma as the input function. Model parameters such as the influx constant (K1) and volume of distribution (VT) were calculated, which reflect the in vivo P-gp function. P-gp and pregnane xenobiotic receptor (PXR) expression levels of the whole brain were assessed using western blot. The administration of MC111 decreased K1 and VT of [18F]MC225 in the whole brain and all of the selected brain regions. In the high-dose group, whole-brain K1 was decreased by 34% (K1-high-dose = 0.20 ± 0.02 vs K1-control = 0.30 ± 0.02; p < 0.001) and in the low-dose group by 7% (K1-low-dose = 0.28 ± 0.02 vs K1-control = 0.30 ± 0.02; p = 0.42) compared to controls. Whole-brain VT was decreased by 25% in the high-dose group (VT-high-dose = 5.92 ± 0.41 vs VT-control = 7.82 ± 0.38; p < 0.001) and by 6% in the low-dose group (VT-low-dose = 7.35 ± 0.38 vs VT-control = 7.82 ± 0.37; p = 0.38) compared to controls. k2 values did not vary after treatment. The treatment did not affect the metabolism of [18F]MC225. Western blot studies using the whole-brain tissue did not detect changes in the P-gp expression, however, preliminary results using isolated brain capillaries found an increasing trend up to 37% in treated rats. The decrease in K1 and VT values after treatment with the inducer indicates an increase in the P-gp functionality at the BBB of treated rats. Moreover, preliminary results using brain endothelial cells also sustained the increase in the P-gp expression. In conclusion, the results verify that MC111 induces P-gp expression and function at the BBB in rats. An increasing trend regarding the P-gp expression levels is found using western blot and an increased P-gp function is confirmed with [18F]MC225 and PET.
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Affiliation(s)
- Lara García-Varela
- Department
of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O.
Box 30001, 9713 GZ Groningen, The Netherlands
| | - Manuel Rodríguez-Pérez
- Clinical
Neurosciences Research Laboratory, Health
Research Institute of Santiago de Compostela (IDIS), 15706 Santiago
de Compostela, Spain
| | - Antía Custodia
- Clinical
Neurosciences Research Laboratory, Health
Research Institute of Santiago de Compostela (IDIS), 15706 Santiago
de Compostela, Spain
| | - Rodrigo Moraga-Amaro
- Department
of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O.
Box 30001, 9713 GZ Groningen, The Netherlands
| | - Nicola A. Colabufo
- Dipartimento
di Farmacia-Scienze del Farmaco, Università
degli Studi di Bari, I-70125 Bari, Italy
| | - Pablo Aguiar
- Department
of Nuclear Medicine and Molecular Imaging Group, Clinical University
Hospital, IDIS Health Research Institute, 15706 Santiago
de Compostela, Spain
| | - Tomás Sobrino
- Clinical
Neurosciences Research Laboratory, Health
Research Institute of Santiago de Compostela (IDIS), 15706 Santiago
de Compostela, Spain
| | - Rudi A.J.O. Dierckx
- Department
of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O.
Box 30001, 9713 GZ Groningen, The Netherlands
| | - Aren van Waarde
- Department
of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O.
Box 30001, 9713 GZ Groningen, The Netherlands
| | - Philip H. Elsinga
- Department
of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O.
Box 30001, 9713 GZ Groningen, The Netherlands
| | - Gert Luurtsema
- Department
of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O.
Box 30001, 9713 GZ Groningen, The Netherlands
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Cardoso ME, Tejería E, Zirbesegger K, Savio E, Terán M, Rey Ríos AM. Development and characterization of two novel 68 Ga-labelled neuropeptide Y short analogues with potential application in breast cancer imaging. Chem Biol Drug Des 2021; 98:182-191. [PMID: 33982434 DOI: 10.1111/cbdd.13864] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 04/05/2021] [Accepted: 05/01/2021] [Indexed: 12/20/2022]
Abstract
In vivo receptor targeting with radiolabelled peptide-based probes is an attractive approach for the development of novel radiotracers for molecular imaging. This work presents the development and characterization of two novel neuropeptide Y analogues labelled with a positron emitter 68 Ga, for potential use in breast cancer imaging. Both analogues share the same amino acid sequence and were derivatized with NOTA through either a lysine linker (L1) or an acetylated lysine (L2). In both cases, a single product with radiochemical purity higher than 95% was obtained. The two complexes were hydrophilic, showed remarkable in vitro stability, good cellular uptake, binding affinity in the nanomolar range and high cellular internalization rate. Biodistribution studies revealed low blood uptake and elimination through the urinary tract. The addition of an acetyl group in the spacer increased the lipophilicity of C2 and modified the reactivity of the ε-amino group of the lysine which resulted in lower protein binding and lower percentage of injected dose in bladder and urine. The tumour versus muscle ratio was (3.8 ± 0.4) for 68 Ga-L1 and (4.7 ± 0.4) for 68 Ga-L2. These results encourage performing further studies in order to complete the evaluation of both tracers as potential radiopharmaceutical for breast cancer imaging.
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Affiliation(s)
- María Elena Cardoso
- Área de Radioquímica, Departamento Estrella Campos, Facultad de Química, Universidad de la República (UdelaR), Montevideo, Uruguay
- Área de Investigación y Desarrollo Biomédico y Químico Farmacéutico, Centro Uruguayo de Imagenología Molecular (CUDIM), Montevideo, Uruguay
- Graduate Program in Chemistry, Facultad de Química, Universidad de la República, Montevideo, Uruguay
| | - Emilia Tejería
- Área de Radioquímica, Departamento Estrella Campos, Facultad de Química, Universidad de la República (UdelaR), Montevideo, Uruguay
| | - Kevin Zirbesegger
- Área de Investigación y Desarrollo Biomédico y Químico Farmacéutico, Centro Uruguayo de Imagenología Molecular (CUDIM), Montevideo, Uruguay
| | - Eduardo Savio
- Área de Investigación y Desarrollo Biomédico y Químico Farmacéutico, Centro Uruguayo de Imagenología Molecular (CUDIM), Montevideo, Uruguay
| | - Mariella Terán
- Área de Radioquímica, Departamento Estrella Campos, Facultad de Química, Universidad de la República (UdelaR), Montevideo, Uruguay
| | - Ana María Rey Ríos
- Área de Radioquímica, Departamento Estrella Campos, Facultad de Química, Universidad de la República (UdelaR), Montevideo, Uruguay
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Shuvaev S, Suturina EA, Rotile NJ, Astashkin A, Ziegler CJ, Ross AW, Walker TL, Caravan P, Taschner IS. Revisiting dithiadiaza macrocyclic chelators for copper-64 PET imaging. Dalton Trans 2020; 49:14088-14098. [PMID: 32970072 PMCID: PMC7967274 DOI: 10.1039/d0dt02787a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Synthesis and characterisation of a dithiadiaza chelator NSNS2A, as well as copper complexes thereof are reported in this paper. Solution structures of copper(i/ii) complexes were calculated using density functional theory (DFT) and validated by both NMR and EPR spectroscopy. DFT calculations revealed a switch in the orientation of tetragonal distortion upon protonation, which might be responsible for poor stability of the Cu(II)NSNS2A complex in aqueous media, whilst the same switch in tetragonal distortion was experimentally observed by changing the solvent. The chelator was radiolabeled with 64Cu and evaluated using PET/MRI in rats. Despite a favorable redox potential to stabilize the cuprous state in vivo, the 64Cu(II)NSNS2A complex showed suboptimal stability compared to its tetraazamacrocyclic analogue, 64Cu(TE2A), with a significant 64Cu uptake in the liver.
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Affiliation(s)
- Sergey Shuvaev
- A. A. Martinos Center for Biomedical Imaging and the Institute for Innovation in Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA.
| | | | - Nicholas J Rotile
- A. A. Martinos Center for Biomedical Imaging and the Institute for Innovation in Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA.
| | - Andrei Astashkin
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721, USA
| | | | - Alana W Ross
- A. A. Martinos Center for Biomedical Imaging and the Institute for Innovation in Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA.
| | - Tia L Walker
- Department of Chemistry, Indiana University Northwest, Gary, IN 46408, USA.
| | - Peter Caravan
- A. A. Martinos Center for Biomedical Imaging and the Institute for Innovation in Imaging, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA.
| | - Ian S Taschner
- Department of Chemistry, Indiana University Northwest, Gary, IN 46408, USA.
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Schildt A, de Vries EFJ, Willemsen ATM, Moraga-Amaro R, Lima-Giacobbo B, Sijbesma JWA, Sossi V, Dierckx RAJO, Doorduin J. Modeling of [ 18F]FEOBV Pharmacokinetics in Rat Brain. Mol Imaging Biol 2020; 22:931-939. [PMID: 31907846 DOI: 10.1007/s11307-019-01466-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE [18F]Fluoroethoxybenzovesamicol ([18F]FEOBV) is a radioligand for the vesicular acetylcholine transporter (VAChT), a marker of the cholinergic system. We evaluated the quantification of [18F]FEOBV in rats in control conditions and after partial saturation of VAChT using plasma and reference tissue input models and test-retest reliability. PROCEDURE Ninety-minute dynamic [18F]FEOBV PET scans with arterial blood sampling were performed in control rats and rats pretreated with 10 μg/kg FEOBV. Kinetic analyses were performed using one- (1TCM) and two-tissue compartmental models (2TCM), Logan and Patlak graphical analyses with metabolite-corrected plasma input, reference tissue Patlak with cerebellum as reference tissue, standard uptake value (SUV) and SUV ratio (SUVR) using 60- or 90-min acquisition. To assess test-retest reliability, two dynamic [18F]FEOBV scans were performed 1 week apart. RESULTS The 1TCM did not fit the data. Time-activity curves were more reliably estimated by the irreversible than the reversible 2TCM for 60 and 90 min as the influx rate Ki showed a lower coefficient of variation (COV, 14-24 %) than the volume of distribution VT (16-108 %). Patlak graphical analysis showed a good fit to the data for both acquisition times with a COV (12-27 %) comparable to the irreversible 2TCM. For 60 min, Logan analysis performed comparably to both irreversible models (COV 14-32 %) but showed lower sensitivity to VAChT saturation. Partial saturation of VAChT did not affect model selection when using plasma input. However, poor correlations were found between irreversible 2TCM and SUV and SUVR in partially saturated VAChT states. Test-retest reliability and intraclass correlation for SUV were good. CONCLUSION [18F]FEOBV is best modeled using the irreversible 2TCM or Patlak graphical analysis. SUV should only be used if blood sampling is not possible.
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Affiliation(s)
- Anna Schildt
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, P.O Box 30.001, Groningen, 9700RB, The Netherlands
- Department of Physics and Astronomy, University of British Columbia, Vancouver, Canada
| | - Erik F J de Vries
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, P.O Box 30.001, Groningen, 9700RB, The Netherlands
| | - Antoon T M Willemsen
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, P.O Box 30.001, Groningen, 9700RB, The Netherlands
| | - Rodrigo Moraga-Amaro
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, P.O Box 30.001, Groningen, 9700RB, The Netherlands
| | - Bruno Lima-Giacobbo
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, P.O Box 30.001, Groningen, 9700RB, The Netherlands
| | - Jürgen W A Sijbesma
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, P.O Box 30.001, Groningen, 9700RB, The Netherlands
| | - Vesna Sossi
- Department of Physics and Astronomy, University of British Columbia, Vancouver, Canada
| | - Rudi A J O Dierckx
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, P.O Box 30.001, Groningen, 9700RB, The Netherlands
| | - Janine Doorduin
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, P.O Box 30.001, Groningen, 9700RB, The Netherlands.
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Hillmer AT, Carson RE. Quantification of PET infusion studies without true equilibrium: A tissue clearance correction. J Cereb Blood Flow Metab 2020; 40:860-874. [PMID: 31088233 PMCID: PMC7168787 DOI: 10.1177/0271678x19850000] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 04/21/2019] [Indexed: 11/16/2022]
Abstract
In some positron emission tomography (PET) studies, a reversibly binding radioligand is administered as a constant infusion to establish true equilibrium for quantification. This approach reduces scanning time and simplifies data analysis, but assumes similar behavior of the radioligand in plasma across the study population to establish true equilibrium in all subjects. Bias in outcome measurements can result if this assumption is not met. This work developed and validated a correction that reduces bias in total distribution volume (VT) estimates when true equilibrium is not present. This correction, termed tissue clearance correction (TCC), took the form V T = V T ( A ) / ( 1 + β γ V T ( A ) ) , where β is the radioligand clearance rate in tissue, γ is a radiotracer-specific constant, and VT(A) is the apparent VT. Simulations characterized the robustness of TCC across imperfect values of γ and β and demonstrated reduction to false positive rates. This approach was validated with human infusion data for three radiotracers: [18F]FPEB, (-)-[18F]flubatine, and [11C]UCB-J. TCC reduced bias in VT estimates for all radiotracers and significantly reduced intersubject variance in VT for [18F]FPEB data in some brain regions. Thus, TCC improves quantification of data acquired from PET infusion studies.
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Affiliation(s)
- Ansel T Hillmer
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, USA
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
- Yale University PET Center, Yale University School of Medicine, New Haven, CT, USA
| | - Richard E Carson
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, USA
- Yale University PET Center, Yale University School of Medicine, New Haven, CT, USA
- Department of Biomedical Engineering, Yale School of Engineering & Applied Science, New Haven, CT, USA
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Bhatt S, Nabulsi NB, Li S, Cai Z, Matuskey D, Bini J, Najafzadeh S, Kapinos M, Ropchan JR, Carson RE, Cosgrove KP, Huang Y, Hillmer AT. First in-human PET study and kinetic evaluation of [ 18F]AS2471907 for imaging 11β-hydroxysteroid dehydrogenase type 1. J Cereb Blood Flow Metab 2020; 40:695-704. [PMID: 30895878 PMCID: PMC7168798 DOI: 10.1177/0271678x19838633] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 02/08/2019] [Accepted: 02/11/2019] [Indexed: 01/11/2023]
Abstract
11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1) catalyzes enzymatic conversion of cortisone into the stress hormone cortisol. This first-in-human brain imaging study characterizes the kinetic modeling and test-retest reproducibility of [18F]AS2471907, a novel PET radiotracer for 11β-HSD1. Eight individuals underwent one 180-min (n = 4) or two 240-min (n = 4) [18F]AS2471907 PET brain scans (12 total) acquired on the high-resolution research tomograph (HRRT) scanner with arterial blood sampling. Imaging data were modeled with 1-tissue (1T) and 2-tissue (2T) compartment models and with multilinear analysis (MA1) to estimate [18F]AS2471907 availability (VT). [18F]AS2471907 demonstrated high, heterogeneous uptake throughout the brain. Of the compartment models, 2T best described [18F]AS2471907 data. Estimates of VT were highly correlated between 2T and MA1 (t* = 30 min) with MA1 yielding VT values ranging from 3.2 ± 1.0 mL/cm3 in the caudate to 15.7 ± 4.2 mL/cm3 in the occipital cortex. The median absolute test-retest variability of 16 ± 5% and high intraclass correlation coefficient (ICC) values of 0.67-0.97 across regions indicate fair test-retest reliability but large intersubject variability. VT estimates using 180 min were within 10% of estimates using full acquisition time. In summary, [18F]AS2471907 exhibits reasonable kinetic properties for imaging 11β-HSD1 in human brain.
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Affiliation(s)
- Shivani Bhatt
- Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT, USA
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, USA
| | - Nabeel B Nabulsi
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, USA
| | - Songye Li
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, USA
| | - Zhengxin Cai
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, USA
| | - David Matuskey
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, USA
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Jason Bini
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, USA
| | - Soheila Najafzadeh
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, USA
| | - Michael Kapinos
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, USA
| | - Jim R Ropchan
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, USA
| | - Richard E Carson
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, USA
| | - Kelly P Cosgrove
- Interdepartmental Neuroscience Program, Yale University School of Medicine, New Haven, CT, USA
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, USA
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
- National Center for PTSD, West Haven VA Hospital, West Haven, CT, USA
| | - Yiyun Huang
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, USA
| | - Ansel T Hillmer
- Yale PET Center, Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, CT, USA
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
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8
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Huang YY, Chiu MJ, Yen RF, Tsai CL, Hsieh HY, Chiu CH, Wu CH, Hsin LW, Tzen KY, Cheng CY, Ma KH, Shiue CY. An one-pot two-step automated synthesis of [18F]T807 injection, its biodistribution in mice and monkeys, and a preliminary study in humans. PLoS One 2019; 14:e0217384. [PMID: 31260447 PMCID: PMC6602418 DOI: 10.1371/journal.pone.0217384] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 05/11/2019] [Indexed: 12/22/2022] Open
Abstract
[18F]T807 is a potent tau protein imaging agent. In order to fulfill the demand from preclinical and clinical studies, we developed an automated one-pot two-step synthesis of this potent tau imaging agent and studied its stability, and dosimetry in mice and monkeys. We also conducted a preliminary study of this imaging agent in humans. Using this one-pot two-step method, the radiochemical yield (RCY) of [18F]T807 was 20.5 ± 6.1% (n = 15) at the end of bombardment (EOB) in a synthesis time of 70±5 min. The chemical and radiochemical purities were >90% and the specific activities were 151 ± 52 GBq/μmol. The quality of [18F]T807 synthesized by this method met the U.S. Pharmacopoeia (USP) criteria. The stability test showed that the [18F]T807 injection was stable at room temperature for up to 4 h after the end of synthesis (EOS). The estimated effective dose of the [18F]T807 injection extrapolated from monkeys was 19 μSv/MBq (n = 2), while the estimated effective doses of the [18F]T807 injection extrapolated from fasted and non-fasted mice were 123 ± 27 (n = 3) and 94 ± 19 (n = 4) μSv/MBq, respectively. This one-pot two-step automated method produced the [18F]T807 injection with high reproducibility and high quality. PET imaging and radiation dosimetry evaluation in mice and Formosan rock monkeys suggested that the [18F]T807 injection synthesized by this method is suitable for use in human PET imaging studies. Thus, this method could fulfill the demand for the [18F]T807 injection in both preclinical and clinical studies of tauopathies, especially for nearby study sites without cyclotrons.
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Affiliation(s)
- Ya-Yao Huang
- PET Center, Department of Nuclear Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Ming-Jang Chiu
- Molecular Imaging Center, National Taiwan University, Taipei, Taiwan
- Departments of Neurology, National Taiwan University Hospital, Taipei, Taiwan
- Institute of Brain and Mind Sciences, College of Medicine, National Taiwan University, Zhongzheng Dist., Taipei, Taiwan
- Department of Psychology, National Taiwan University, Taipei, Taiwan
- Graduate Institute of Biomedical Engineering and Bio-informatics, National Taiwan University, Taipei, Taiwan
| | - Ruoh-Fang Yen
- PET Center, Department of Nuclear Medicine, National Taiwan University Hospital, Taipei, Taiwan
- Molecular Imaging Center, National Taiwan University, Taipei, Taiwan
- Department of Radiology, National Taiwan University College of Medicine, Taipei, Taiwan
| | - Chia-Ling Tsai
- PET Center, Department of Nuclear Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Hao-Yu Hsieh
- School of Pharmacy, College of Medicine, National Taiwan University, Zhongzheng Dist., Taipei, Taiwan
| | - Ching-Hung Chiu
- PET Center, Department of Nuclear Medicine, National Taiwan University Hospital, Taipei, Taiwan
| | - Chi-Han Wu
- Molecular Imaging Center, National Taiwan University, Taipei, Taiwan
| | - Ling-Wei Hsin
- Molecular Imaging Center, National Taiwan University, Taipei, Taiwan
- School of Pharmacy, College of Medicine, National Taiwan University, Zhongzheng Dist., Taipei, Taiwan
| | - Kai-Yuan Tzen
- PET Center, Department of Nuclear Medicine, National Taiwan University Hospital, Taipei, Taiwan
- Molecular Imaging Center, National Taiwan University, Taipei, Taiwan
| | - Cheng-Yi Cheng
- PET Center, Department of Nuclear Medicine, Tri-Service General Hospital, Neihu, Taipei, Taiwan
| | - Kuo-Hsing Ma
- Department of Biology and Anatomy, National Defense Medical Center, Taipei, Taiwan
| | - Chyng-Yann Shiue
- PET Center, Department of Nuclear Medicine, National Taiwan University Hospital, Taipei, Taiwan
- Molecular Imaging Center, National Taiwan University, Taipei, Taiwan
- PET Center, Department of Nuclear Medicine, Tri-Service General Hospital, Neihu, Taipei, Taiwan
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Denk C, Wilkovitsch M, Aneheim E, Herth MM, Jensen H, Lindegren S, Mikula H. Multifunctional Clickable Reagents for Rapid Bioorthogonal Astatination and Radio-Crosslinking. Chempluschem 2019; 84:775-778. [PMID: 31681526 PMCID: PMC6813637 DOI: 10.1002/cplu.201900114] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2019] [Indexed: 11/11/2022]
Abstract
In the past decade, several developments have expanded the chemical toolbox for astatination and the preparation of 211At-labeled radiopharmaceuticals. However, there is still a need for advanced methods for the synthesis of astatinated (bio)molecules to address challenges such as limited in vivo stability. Herein, we report the development of multifunctional 211At-labeled reagents that can be prepared by applying a modular and versatile click approach for rapid assembly. The introduction of tetrazines as bioorthogonal tags enables rapid radiolabeling and radio-crosslinking, which is demonstrated by steric shielding of 211At to significantly increase label stability in human blood plasma.
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Affiliation(s)
- Christoph Denk
- Institute of Applied Synthetic ChemistryVienna University of Technology (TU Wien)Getreidemarkt 9/1631060ViennaAustria
| | - Martin Wilkovitsch
- Institute of Applied Synthetic ChemistryVienna University of Technology (TU Wien)Getreidemarkt 9/1631060ViennaAustria
| | - Emma Aneheim
- Department of Radiation Physics Institute for Clinical SciencesSahlgrenska Academy at University of GothenburgGula Stråket 2b41345GothenburgSweden
| | - Matthias M. Herth
- Department of Drug Design and PharmacologyUniversity of Copenhagen2100CopenhagenDenmark
- Department of Clinical PhysiologyNuclear Medicine & PET RigshospitaletBlegdamsvej 92100Copenhagen (Denmark
| | - Holger Jensen
- Department of Clinical PhysiologyNuclear Medicine & PET RigshospitaletBlegdamsvej 92100Copenhagen (Denmark
| | - Sture Lindegren
- Department of Radiation Physics Institute for Clinical SciencesSahlgrenska Academy at University of GothenburgGula Stråket 2b41345GothenburgSweden
| | - Hannes Mikula
- Institute of Applied Synthetic ChemistryVienna University of Technology (TU Wien)Getreidemarkt 9/1631060ViennaAustria
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10
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Abstract
Cardiac 123I-metaiodobenzylguanidine (MIBG) scintigraphy is a promising biomarker for dementia with Lewy bodies (DLB). However, we experienced a patient with cognitive decline, parkinsonism, and a decreased MIBG uptake who turned out to have HIV dementia. Normal dopamine transporter single-photon emission computed tomography reduced the possibility of comorbid Lewy body pathology causing the patient' s parkinsonism. The decreased MIBG uptake was most likely due to postganglionic sympathetic nerve denervation, which can also be caused by HIV. This case further emphasizes the importance of excluding other causes of autonomic neuropathy, including HIV infection, before interpreting MIBG scans.
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Affiliation(s)
- Masanori Kurihara
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Japan
| | - Takuya Sasaki
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Japan
| | - Hiroyuki Ishiura
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Japan
| | - Shoji Tsuji
- Department of Neurology, Graduate School of Medicine, The University of Tokyo, Japan
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11
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Liu G, Hu Y, Zhao Y, Yu H, Hu P, Shi H. Variations of the liver standardized uptake value in relation to background blood metabolism: An 2-[18F]Fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography study in a large population from China. Medicine (Baltimore) 2018; 97:e0699. [PMID: 29742723 PMCID: PMC5959431 DOI: 10.1097/md.0000000000010699] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
To investigate the influence of background blood metabolism on liver uptake of 2-[F]fluoro-2-deoxy-D-glucose (F-FDG) and search for an appropriate corrective method.Positron emission tomography/computed tomography (PET/CT) and common serological biochemical tests of 633 healthy people were collected retrospectively. The mean standardized uptake value (SUV) of the liver, liver artery, and portal vein (i.e., SUVL, SUVA, and SUVP) were measured. SUVL/A was calculated as SUVL/SUVA, while SUVL/P was calculated as SUVL/SUVP. SUV of liver parenchyma (SUVLP) was calculated as SUVL - .3 × (.75 × SUVP + .25 × SUVA). The coefficients of variation (CV) of SUVL, SUVL/A, SUVL/P, and SUVLP were compared to assess their interindividual variations. Univariate and multivariate analyses were performed to identify vulnerabilities of these SUV indexes to common factors assessed using serological liver functional tests.SUVLP was significantly larger than SUVL (2.19 ± .497 vs 1.88 ± .495, P < .001), while SUVL/P was significantly smaller than SUVL (1.72 ± .454 vs 1.88 ± .495, P < .001). The difference between SUVL/A and SUVL was not significant (1.83 ± .500 vs 1.88 ± .495, P = .130). The CV of SUVLP (22.7%) was significantly smaller than that of SUVL (22.7%:26.3%, P < .001), while the CVs of SUVL/A (27.2%) and SUVL/P (26.4%) were not different from that of SUVL (P = .429 and .929, respectively). Fewer variables independently influenced SUVLP than influenced SUVL, SUVL/A, and SUVL/P; Only aspartate aminotransferase, body mass index, and total cholesterol, all P-values <.05.The activity of background blood influences the variation of liver SUV. SUVLP might be an alternative corrective method to reduce this influence, as its interindividual variation and vulnerability to effects from common factors of serological liver functional tests are relatively lower than the commonly used SUVL.
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12
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Schoen M, Braun T, Manava P, Ludwigs S, Lell M. Influence of scan time point and volume of intravenous contrast administration on blood-pool and liver SUVmax and SUVmean in [18F] FDG PET/CT. Nuklearmedizin 2018; 57:50-55. [PMID: 29590675 DOI: 10.3413/nukmed-0919-17-08] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIM To investigate the influence of scan time point and volume of intravenous contrast material in 18F-FDG PET/CT on maximum and mean standardized uptake values (SUVmax/mean) in bloodpool and liver. METHODS In 120 patients scheduled for routine whole-body 18F-FDG PET/CT the maximum and mean standardized uptake values (SUVmax/SUVmean) in the liver and blood pool were measured after varying scan time-point (delay 0 s-140 s post injectionem) and volume of contrast material (CM; 0 ml, 80 ml, 100 ml of 300 mg/ml of Iodine). Six groups of 20 patients were investigated: (1) without intravenous CM, (2-5) injection of 100 ml CM with a delay of 80 s (2), 100 s (3), 120 s (4), 140 s (5), and 80 ml CM and a delay of 100 s (6). SUVmax, SUVmean, maximum Hounsfield units (HUmax) and average Hounsfield units (HUav) were calculated with the use of manually drawn regions of interests (ROIs) over the aortic arch and healthy liver tissue. RESULTS SUVmax in bloodpool was significantly higher in group 3, 4 and 6 compared to group 1. Groups 2 and 5 also showed higher mean values of SUVmax, but the difference was not significant. SUVmean in bloodpool was also higher in groups 2, 3, 4, 5 and 6 compared to group 1, but the differences were only statistically significant in group 3. Both SUVmax and SUVmean in healthy liver tissue did not show significant differences when compared to the non contrast-enhanced control group. CONCLUSION SUVmax and to a lesser extent SUVmean measured in CM enhanced FDG PET/CT in blood pool could be significantly altered in high contrast CT examinations. This should be kept in mind in PET/CT protocols and evaluation relying on SUVmax and SUVmean, for example when used in the assessment of therapy response, especially in highly vascularized tumor lesions. ZIEL:: Das Ziel dieser Studie war den Einfluss von unterschiedlichen Messzeitpunkten und Volumina bei der Gabe von intravenösem Kontrastmittel in der 18F-FDG PET/CT auf SUVmax und SUVmean im Blutpool und Lebergewebe zu untersuchen. METHODEN In 120 Patienten, geplant für eine Ganzkörper 18F-FDG -PET/CT, wurden die maximalen und durchschnittlichen standardisierten Aufnahmewerte (SUVmax/SUVmean) in der Leber und im Blutpool, jeweils nach unterschiedlichen Messzeitpunkten (Verzögerung 0 s-140 s post injectionem) und verschiedenen Volumina von Kontrastmittel (KM; 0 ml, 80 ml, 100 ml mit einer Konzentration von 300 mg/ml Jod) gemessen. Sechs Gruppen von je 20 Patienten wurden untersucht: (1) ohne intravenöses KM, (2-5) Injektion von 100 ml KM mit einer Verzögerung von 80 s (2), 100 s (3), 120 s (4), 140 s (5), und 80 ml KM mit einer Verzögerung von 100 s (6). Es wurden jeweils die SUVmax, SUVmean, die maximalen and die durchschnittlichen Hounsfield Einheiten (HUav, HUmax) anhand manuell gezeichneter Bereiche von Interesse (ROIs) im Aortenbogen und im gesunden Lebergewebe berechnet. ERGEBNISSE Die SUVmax im Blutpool waren im Vergleich zur Gruppe 1 signifikant höher in Gruppe 3, 4 und 6. Die Gruppen 2 und 5 zeigten ebenfalls höhere Durchschnittswerte von SUVmax, der Unterschied war jedoch nicht signifikant. Die SUVmean im Blutpool waren im Vergleich zur Gruppe 1 ebenfalls höher in den Gruppen 2, 3, 4, 5 und 6, allerdings waren die Unterschiede nur in Gruppe 3 statistisch signifikant. Im Lebergewebe zeigten sowohl SUVmax, als auch SUVmean keine signifikanten Unterschiede im Vergleich zu der nativen Kontrollgruppe. SCHLUSSFOLGERUNGEN In der Kontrastmittel-gestützten FDG PET/CT können die SUVmax und in geringerem Ausmaß auch SUVmean im Blutpool durch Hochkontrast-CT Untersuchungen signifikant beeinflusst werden. Dies sollte bei PET/CT Protokollen bzw. Auswertungen, die auf SUVmax und SUVmean beruhen, berücksichtigt werden, zum Beispiel bei der Beurteilung des Therapieansprechens insbesondere bei stark vaskularisiertem Tumorgewebe.
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Bokhari TH, Roohi S, Hina S, Saeed S. Synthesis, optimization and biological evaluation of 99mTc-digoxin as possible cardiac imaging agent. Pak J Pharm Sci 2018; 31:19-24. [PMID: 29348079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Heart imaging radiopharmaceuticals could improve the diagnostic value of routine heart scanning for detecting cardiac disorders. The aim of the study was to prepare high radiochemical purity 99mTc-Digoxin in a yield of about 98%. The optimal conditions for labelling were as follows: 100μg of Digoxin, 2μg of SnCl<inf>2</inf>•2H<inf>2</inf>O, room temperature (25±1°C), reaction retention time of 30 min at pH 7. Under these conditions, the radiochemical yield of 99mTc-Digoxin reaches 98%. In vivo bio distribution was performed in normal Swiss Albino mice at different time intervals after administration of 99mTc-Digoxin.Scintigraphic study of 99mTc-Digoxin was performed in rabbits. The heart uptake of 99mTc-Digoxin was sufficiently high and thus may be a potential myocardial imaging radiopharmaceutical applicable in cardiology.
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Affiliation(s)
| | - Samina Roohi
- Isotope Production Division, Pakistan Institute of Nuclear Science and Technology, P.O. Nilore, Islamabad, Pakistan
| | - Saira Hina
- Government College Women University, Faisalabad, Pakistan
| | - Shabana Saeed
- Pakistan Institute of Engineering and Applied Sciences, P. O. Nilore, Islamabad, Pakistan
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Abstract
The pharmacokinetic equations of Pierson et al. describing the behavior of bromide in rat provide a general approach to the modeling of extracellular fluid (ECF). The movement of material into ECF spaces is rapid and is completely characterized by tissue volumes and vascular flow rates to and from a tissue, the volumes of the tissue, and the ECF associated with the tissue. Early-time measurements are needed to characterize ECF. Measurements of DTPA disappearance from plasma by Wedeking et al. are discussed as an example of such measurements. In any biokinetic model, the fastest transfer rates are not determinable with the usual datasets, and if determined empirically, these rates will have very large and highly correlated uncertainties, so particular values of these rates, even though the model fits the available data, are not significant. A pharmacokinetic front-end provides values for these fast rates. An example of such a front-end for a 200-g rat is given.
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Affiliation(s)
- Guthrie Miller
- *Santa Fe, NM; †Radiation Protection Division, Los Alamos National Laboratory, Los Alamos, NM; ‡Melohill Technology, LLC, Rockville, MD
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Prabhakaran J, Zanderigo F, Solingapuram Sai KK, Rubin-Falcone H, Jorgensen MJ, Kaplan JR, Mintz A, Mann JJ, Dileep Kumar JS. Radiosynthesis and in Vivo Evaluation of [ 11C]A1070722, a High Affinity GSK-3 PET Tracer in Primate Brain. ACS Chem Neurosci 2017; 8:1697-1703. [PMID: 28485573 PMCID: PMC5559324 DOI: 10.1021/acschemneuro.6b00376] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Dysfunction of glycogen synthase kinase 3 (GSK-3) is implicated in the etiology of Alzheimer's disease, Parkinson's disease, diabetes, pain, and cancer. A radiotracer for functional positron emission tomography (PET) imaging could be used to study the kinase in brain disorders and to facilitate the development of small molecule inhibitors of GSK-3 for treatment. At present, there is no target-specific or validated PET tracer available for the in vivo monitoring of GSK-3. We radiolabeled the small molecule inhibitor [11C]1-(7-methoxy- quinolin-4-yl)-3-(6-(trifluoromethyl)pyridin-2-yl)urea ([11C]A1070722) with high affinity to GSK-3 (Ki = 0.6 nM) in excellent radiochemical yield. PET imaging experiments in anesthetized vervet/African green monkey exhibited that [11C]A1070722 penetrated the blood-brain barrier (BBB) and accumulated in brain regions, with highest radioactivity binding in frontal cortex followed by parietal cortex and anterior cingulate, and with the lowest bindings found in caudate, putamen, and thalamus, similarly to the known distribution of GSK-3 in human brain. Our studies suggest that [11C]A1070722 can be a potential PET radiotracer for the in vivo quantification of GSK-3 in brain.
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Affiliation(s)
- Jaya Prabhakaran
- Department of Psychiatry, Columbia University Medical Center, New York, New York 10032, United States
- Division of Molecular Imaging and Neuropathology, New York State Psychiatric Institute, New York, New York 10032, United States
| | - Francesca Zanderigo
- Department of Psychiatry, Columbia University Medical Center, New York, New York 10032, United States
- Division of Molecular Imaging and Neuropathology, New York State Psychiatric Institute, New York, New York 10032, United States
| | - Kiran Kumar Solingapuram Sai
- Department of Radiology, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27101, United States
| | - Harry Rubin-Falcone
- Department of Psychiatry, Columbia University Medical Center, New York, New York 10032, United States
| | - Matthew J. Jorgensen
- Department of Pathology, Section on Comparative Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina 27101, United States
| | - Jay R. Kaplan
- Department of Pathology, Section on Comparative Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina 27101, United States
| | - Akiva Mintz
- Department of Radiology, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27101, United States
| | - J. John Mann
- Department of Psychiatry, Columbia University Medical Center, New York, New York 10032, United States
- Division of Molecular Imaging and Neuropathology, New York State Psychiatric Institute, New York, New York 10032, United States
| | - J. S. Dileep Kumar
- Division of Molecular Imaging and Neuropathology, New York State Psychiatric Institute, New York, New York 10032, United States
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Norquay G, Leung G, Stewart NJ, Wolber J, Wild JM. 129 Xe chemical shift in human blood and pulmonary blood oxygenation measurement in humans using hyperpolarized 129 Xe NMR. Magn Reson Med 2017; 77:1399-1408. [PMID: 27062652 PMCID: PMC5363245 DOI: 10.1002/mrm.26225] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Revised: 02/25/2016] [Accepted: 02/29/2016] [Indexed: 12/22/2022]
Abstract
PURPOSE To evaluate the dependency of the 129 Xe-red blood cell (RBC) chemical shift on blood oxygenation, and to use this relation for noninvasive measurement of pulmonary blood oxygenation in vivo with hyperpolarized 129 Xe NMR. METHODS Hyperpolarized 129 Xe was equilibrated with blood samples of varying oxygenation in vitro, and NMR was performed at 1.5 T and 3 T. Dynamic in vivo NMR during breath hold apnea was performed at 3 T on two healthy volunteers following inhalation of hyperpolarized 129 Xe. RESULTS The 129 Xe chemical shift in RBCs was found to increase nonlinearly with blood oxygenation at 1.5 T and 3 T. During breath hold apnea, the 129 Xe chemical shift in RBCs exhibited a periodic time modulation and showed a net decrease in chemical shift of ∼1 ppm over a 35 s breath hold, corresponding to a decrease of 7-10 % in RBC oxygenation. The 129 Xe-RBC signal amplitude showed a modulation with the same frequency as the 129 Xe-RBC chemical shift. CONCLUSION The feasibility of using the 129 Xe-RBC chemical shift to measure pulmonary blood oxygenation in vivo has been demonstrated. Correlation between 129 Xe-RBC signal and 129 Xe-RBC chemical shift modulations in the lung warrants further investigation, with the aim to better quantify temporal blood oxygenation changes in the cardiopulmonary vascular circuit. Magn Reson Med 77:1399-1408, 2017. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
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Affiliation(s)
- Graham Norquay
- Unit of Academic Radiology, Department of Cardiovascular ScienceUniversity of SheffieldSheffieldSouth YorkshireUnited Kingdom
| | - General Leung
- Unit of Academic Radiology, Department of Cardiovascular ScienceUniversity of SheffieldSheffieldSouth YorkshireUnited Kingdom
| | - Neil J. Stewart
- Unit of Academic Radiology, Department of Cardiovascular ScienceUniversity of SheffieldSheffieldSouth YorkshireUnited Kingdom
| | - Jan Wolber
- Unit of Academic Radiology, Department of Cardiovascular ScienceUniversity of SheffieldSheffieldSouth YorkshireUnited Kingdom
- GE HealthcareAmershamBuckinghamshireUnited Kingdom
| | - Jim M. Wild
- Unit of Academic Radiology, Department of Cardiovascular ScienceUniversity of SheffieldSheffieldSouth YorkshireUnited Kingdom
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Wood AJ, Churilov L, Perera N, Thomas D, Poon A, MacIsaac RJ, Jerums G, Ekinci EI. Estimating glomerular filtration rate: Performance of the CKD-EPI equation over time in patients with type 2 diabetes. J Diabetes Complications 2016; 30:49-54. [PMID: 26597601 DOI: 10.1016/j.jdiacomp.2015.08.025] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2015] [Revised: 08/30/2015] [Accepted: 08/31/2015] [Indexed: 02/03/2023]
Abstract
AIMS To assess the performance of the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation at baseline and longitudinally in people with type 2 diabetes. METHODS Adults with type 2 diabetes attending Austin Health, Melbourne, with≥3 prospective GFR measurements were included in this retrospective study. Plasma disappearance rate of DTPA (diethylene-triamine-penta-acetic acid) was used to calculate measured GFR (mGFR) and compared to estimated GFR (eGFR). The agreement between mGFR and eGFR was estimated using Intraclass Correlation Coefficient (ICC). RESULTS 152 patients had a median of 4 (IQR: 3, 5) mGFR measurements over a period of 11years (IQR: 9, 12). The difference between mGFR and eGFR increased proportionally to the magnitude of the GFR, increasing by 0.2ml/min/1.73m(2) for every 1ml/min/1.73m(2) increase in mGFR, indicative of proportional bias. At lower mGFR levels, eGFR overestimated mGFR, and at higher mGFR levels, eGFR underestimated mGFR. There was a significant association between LDL cholesterol, triglycerides, HbA1c, diastolic blood pressure and the difference between mGFR and eGFR. CONCLUSIONS The CKD-EPI formula underestimates mGFR and the rate of decline of mGFR in patients with type 2 diabetes with an mGFR greater than 60ml/min/1.73m(2). The association between LDL cholesterol, triglycerides, HbA1c, diastolic blood pressure and the difference between mGFR and eGFR warrants further study.
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Affiliation(s)
- Anna J Wood
- Austin Health Endocrine Centre, Heidelberg, VIC, Australia
| | - Leonid Churilov
- Florey Institute of Neuroscience and Mental Health, Heidelberg, VIC, Australia; RMIT University, Melbourne, VIC, Australia
| | - Nayomi Perera
- Austin Health Endocrine Centre, Heidelberg, VIC, Australia
| | - David Thomas
- Austin Health Nuclear Medicine Department, Heidelberg, VIC, Australia
| | - Aurora Poon
- Austin Health Nuclear Medicine Department, Heidelberg, VIC, Australia
| | - Richard J MacIsaac
- Department of Medicine Austin Health, The University of Melbourne, Melbourne, VIC, Australia; Department of Endocrinology and Diabetes, St Vincent's Hospital, The University of Melbourne, Melbourne, VIC, Australia
| | - George Jerums
- Austin Health Endocrine Centre, Heidelberg, VIC, Australia; Department of Medicine Austin Health, The University of Melbourne, Melbourne, VIC, Australia
| | - Elif I Ekinci
- Austin Health Endocrine Centre, Heidelberg, VIC, Australia; Department of Medicine Austin Health, The University of Melbourne, Melbourne, VIC, Australia; Menzies School of Health Research, Darwin, NT, Australia.
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Abstract
Histological analysis of endomyocardial tissue is still the gold standard for the diagnosis of cardiac amyloidosis, but has its limitations. Accordingly, there is a need for non-invasive modalities to diagnose cardiac amyloidosis. Echocardiography and ultrasound and magnetic resonance imaging can show characteristics which may not be very specific for cardiac amyloid. Nuclear medicine has gained a precise role in this context: several imaging modalities have become available for the diagnosis and prognostic stratification of cardiac amyloidosis during the last two decades. The different classes of radiopharmaceuticals have the potential to bind different constituents of the amyloidotic infiltrates, with some relevant differences among the various aetiologic types of amyloidosis and the different organs and tissues involved. This review focuses on the background of the commonly used modalities, their present clinical applications, and future clinical perspectives in imaging patients with (suspected) cardiac amyloidosis. The main focus is on conventional nuclear medicine (bone scintigraphy, cardiac sympathetic innervation) and positron emission tomography.
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Affiliation(s)
- Walter Noordzij
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Center Groningen, PO Box 30.001, 9700 RB, Groningen, The Netherlands,
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Chong HS, Chen Y, Kang CS, Sun X, Wu N. Novel (64)Cu-radiolabeled bile acid conjugates for targeted PET imaging. Bioorg Med Chem Lett 2015; 25:1082-5. [PMID: 25661712 PMCID: PMC4706377 DOI: 10.1016/j.bmcl.2015.01.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 01/01/2015] [Accepted: 01/05/2015] [Indexed: 11/24/2022]
Abstract
A promising bifunctional chelate (N-NE3TA) was conjugated to bile acids, cholic acid (CA), deoxycholic acid (DCA), and chenodeoxycholic acid (CDCA) as tumor targeting vectors. Bile acid conjugates of N-NE3TA (CA-N-NE3TA, DCA-N-NE3TA, and CDCA-N-NE3TA) were comparatively evaluated for complexation with (64)Cu, an imaging probe for positron emission tomography (PET). N-NE3TA-bile acid conjugates were evaluated for radiolabeling kinetics with (64)Cu, and the corresponding (64)Cu-radiolabeled conjugates were screened for complex stability in human serum and EDTA solution. The NE3TA-bile acid conjugates instantly bound to (64)Cu with excellent radiolabeling efficiency at room temperature. All NE3TA-bile acid conjugates radiolabeled with (64)Cu remained inert in human serum for 2days without releasing a considerable amount of the radioactivity. The (64)Cu-radiolabeled complexes were further challenged by EDTA in a 100-fold molar excess. Bile acid-N-NE3TA conjugates radiolabeled with (64)Cu were quite stable with a minimal transfer of (64)Cu to EDTA at 4h time point. The in vitro data indicate that the bile acid-N-NE3TA conjugates deserve further biological evaluation for (64)Cu-based targeted PET imaging applications.
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Affiliation(s)
- Hyun-Soon Chong
- Chemistry Division, Department of Biological and Chemical Sciences, Illinois Institute of Technology, 3101 S. Dearborn St., LS 182, Chicago, IL 60616, United States.
| | - Yunwei Chen
- Chemistry Division, Department of Biological and Chemical Sciences, Illinois Institute of Technology, 3101 S. Dearborn St., LS 182, Chicago, IL 60616, United States
| | - Chi Soo Kang
- Chemistry Division, Department of Biological and Chemical Sciences, Illinois Institute of Technology, 3101 S. Dearborn St., LS 182, Chicago, IL 60616, United States
| | - Xiang Sun
- Chemistry Division, Department of Biological and Chemical Sciences, Illinois Institute of Technology, 3101 S. Dearborn St., LS 182, Chicago, IL 60616, United States
| | - Ningjie Wu
- Chemistry Division, Department of Biological and Chemical Sciences, Illinois Institute of Technology, 3101 S. Dearborn St., LS 182, Chicago, IL 60616, United States
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Huang HJ, Isakow W, Byers DE, Engle JT, Griffin EA, Kemp D, Brody SL, Gropler RJ, Miller JP, Chu W, Zhou D, Pierce RA, Castro M, Mach RH, Chen DL. Imaging pulmonary inducible nitric oxide synthase expression with PET. J Nucl Med 2015; 56:76-81. [PMID: 25525182 PMCID: PMC4501590 DOI: 10.2967/jnumed.114.146381] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
UNLABELLED Inducible nitric oxide synthase (iNOS) activity increases in acute and chronic inflammatory lung diseases. Imaging iNOS expression may be useful as an inflammation biomarker for monitoring lung disease activity. We developed a novel tracer for PET that binds to iNOS in vivo, (18)F-NOS. In this study, we tested whether (18)F-NOS could quantify iNOS expression from endotoxin-induced lung inflammation in healthy volunteers. METHODS Healthy volunteers were screened to exclude cardiopulmonary disease. Qualifying volunteers underwent a baseline, 1-h dynamic (18)F-NOS PET/CT scan. Endotoxin (4 ng/kg) was then instilled bronchoscopically in the right middle lobe. (18)F-NOS imaging was performed again approximately 16 h after endotoxin instillation. Radiolabeled metabolites were determined from blood samples. Cells recovered by bronchoalveolar lavage (BAL) after imaging were stained immunohistochemically for iNOS. (18)F-NOS uptake was quantified as the distribution volume ratio (DVR) determined by Logan plot graphical analysis in volumes of interest placed over the area of endotoxin instillation and in an equivalent lung region on the left. The mean Hounsfield units (HUs) were also computed using the same volumes of interest to measure density changes. RESULTS Seven healthy volunteers with normal pulmonary function completed the study with evaluable data. The DVR increased by approximately 30%, from a baseline mean of 0.42 ± 0.07 to 0.54 ± 0.12, and the mean HUs by 11% after endotoxin in 6 volunteers who had positive iNOS staining in BAL cells. The DVR did not change in the left lung after endotoxin. In 1 volunteer with low-level iNOS staining in BAL cells, the mean HUs increased by 7% without an increase in DVR. Metabolism was rapid, with approximately 50% of the parent compound at 5 min and 17% at 60 min after injection. CONCLUSION (18)F-NOS can be used to image iNOS activity in acute lung inflammation in humans and may be a useful PET tracer for imaging iNOS expression in inflammatory lung disease.
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Affiliation(s)
- Howard J Huang
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Warren Isakow
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Derek E Byers
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Jacquelyn T Engle
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri
| | - Elizabeth A Griffin
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri
| | - Debra Kemp
- Center for Clinical Studies, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri; and
| | - Steven L Brody
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri
| | - Robert J Gropler
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri
| | - J Philip Miller
- Division of Biostatistics, Washington University School of Medicine, St. Louis, Missouri
| | - Wenhua Chu
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri
| | - Dong Zhou
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri
| | - Richard A Pierce
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Mario Castro
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri
| | - Robert H Mach
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri
| | - Delphine L Chen
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri
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Li WB, Klein W, Blanchardon E, Puncher M, Leggett RW, Oeh U, Breustedt B, Noßke D, Lopez MA. Parameter uncertainty analysis of a biokinetic model of caesium. Radiat Prot Dosimetry 2015; 163:37-57. [PMID: 24743755 DOI: 10.1093/rpd/ncu055] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Parameter uncertainties for the biokinetic model of caesium (Cs) developed by Leggett et al. were inventoried and evaluated. The methods of parameter uncertainty analysis were used to assess the uncertainties of model predictions with the assumptions of model parameter uncertainties and distributions. Furthermore, the importance of individual model parameters was assessed by means of sensitivity analysis. The calculated uncertainties of model predictions were compared with human data of Cs measured in blood and in the whole body. It was found that propagating the derived uncertainties in model parameter values reproduced the range of bioassay data observed in human subjects at different times after intake. The maximum ranges, expressed as uncertainty factors (UFs) (defined as a square root of ratio between 97.5th and 2.5th percentiles) of blood clearance, whole-body retention and urinary excretion of Cs predicted at earlier time after intake were, respectively: 1.5, 1.0 and 2.5 at the first day; 1.8, 1.1 and 2.4 at Day 10 and 1.8, 2.0 and 1.8 at Day 100; for the late times (1000 d) after intake, the UFs were increased to 43, 24 and 31, respectively. The model parameters of transfer rates between kidneys and blood, muscle and blood and the rate of transfer from kidneys to urinary bladder content are most influential to the blood clearance and to the whole-body retention of Cs. For the urinary excretion, the parameters of transfer rates from urinary bladder content to urine and from kidneys to urinary bladder content impact mostly. The implication and effect on the estimated equivalent and effective doses of the larger uncertainty of 43 in whole-body retention in the later time, say, after Day 500 will be explored in a successive work in the framework of EURADOS.
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Affiliation(s)
- W B Li
- HMGU-Research Unit Medical Radiation Physics and Diagnostics, Helmholtz Zentrum München - German Research Center for Environmental Health (GmbH), Neuherberg D-85764, Germany
| | - W Klein
- KIT-Institute for Nuclear Waste Disposal, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen 76344, Germany
| | - E Blanchardon
- IRSN-Internal Dose Assessment Lab., PRP-HOM/SDI/LEDI, BP-17, Fontenay-aux-Roses Cedex F-92262, France
| | - M Puncher
- PHE-Department of Toxicology, Centre for Radiation, Chemical and Environmental Hazards, Public Health England, Chilton, Didcot OX11 0RQ, UK
| | - R W Leggett
- Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - U Oeh
- HMGU-Research Unit Medical Radiation Physics and Diagnostics, Helmholtz Zentrum München - German Research Center for Environmental Health (GmbH), Neuherberg D-85764, Germany
| | - B Breustedt
- KIT-Safety Management, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, Eggenstein-Leopoldshafen 76344, Germany
| | - D Noßke
- BfS-Department of Radiation Protection and Health, Ingolstädter Landstr. 1, Oberschleißheim 85764, Germany
| | - M A Lopez
- CIEMAT-Dosimetría Interna, Departamento de Medio Ambiente, Avda Complutense 40, Madrid 28040, Spain
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Senda M, Sasaki M, Yamane T, Shimizu K, Patt M, Barthel H, Sattler B, Nagasawa T, Schultze-Mosgau M, Aitoku Y, Dinkelborg L, Sabri O. Ethnic comparison of pharmacokinetics of (18)F-florbetaben, a PET tracer for beta-amyloid imaging, in healthy Caucasian and Japanese subjects. Eur J Nucl Med Mol Imaging 2014; 42:89-96. [PMID: 25143073 PMCID: PMC4244559 DOI: 10.1007/s00259-014-2890-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 07/31/2014] [Indexed: 11/27/2022]
Abstract
PURPOSE (18)F-Florbetaben is a positron emission tomography (PET) tracer indicated for imaging cerebral beta-amyloid deposition in adult patients with cognitive impairment who are being evaluated for Alzheimer's disease and other causes of cognitive decline. The present study examined ethnic comparability of the plasma pharmacokinetics, which is the input to the brain, between Caucasian and Japanese subjects. METHODS Two identical phase I trials were performed in 18 German and 18 Japanese healthy volunteers to evaluate the plasma pharmacokinetics of a single dose of 300 MBq (18)F-florbetaben, either of low (≤5 μg, LD) or high (50-55 μg, HD) mass dose. Pharmacokinetic parameters were evaluated based on the total (18)F radioactivity measurements in plasma followed by metabolite analysis using radio-HPLC. RESULTS The pharmacokinetics of (18)F-florbetaben was characterized by a rapid elimination from plasma. The dose-normalized areas under the curve of (18)F-florbetaben in plasma as an indicator of the input to the brain were comparable between Germans (LD: 0.38 min/l, HD: 0.55 min/l) and Japanese (LD: 0.35 min/l, HD: 0.45 min/l) suggesting ethnic similarity, and the mass dose effect was minimal. A polar metabolite fraction was the main radiolabelled degradation product in plasma and was also similar between the doses and the ethnic groups. CONCLUSION Absence of a difference in the pharmacokinetics of (18)F-florbetaben in Germans and Japanese has warranted further global development of the PET imaging agent.
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Affiliation(s)
- Michio Senda
- Division of Molecular Imaging, Institute of Biomedical Research and Innovation, 2-2 Minatojima-Minamimachi, Chuo-ku, Kobe, 650-0047, Japan,
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Huang J, O’Sullivan F. An analysis of whole body tracer kinetics in dynamic PET studies with application to image-based blood input function extraction. IEEE Trans Med Imaging 2014; 33:1093-108. [PMID: 24770914 PMCID: PMC4130476 DOI: 10.1109/tmi.2014.2305113] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
In a positron emission tomography (PET) study, the local uptake of the tracer is dependent on vascular delivery and retention. For dynamic studies the measured uptake time-course information can be best interpreted when knowledge of the time-course of tracer in the blood is available. This is certainly true for the most established tracers such as 18F-Fluorodeoxyglucose (FDG) and 15O-Water (H2O). Since direct sampling of blood as part of PET studies is increasingly impractical, there is ongoing interest in image-extraction of blood time-course information. But analysis of PET-measured blood pool signals is complicated because they will typically involve a combination of arterial, venous and tissue information. Thus, a careful appreciation of these components is needed to interpret the available data. To facilitate this process, we propose a novel Markov chain model for representation of the circulation of a tracer atom in the body. The model represents both arterial and venous time-course patterns. Under reasonable conditions equilibration of tracer activity in arterial and venous blood is achieved by the end of the PET study-consistent with empirical measurement. Statistical inference for Markov model parameters is a challenge. A penalized nonlinear least squares process, incorporating a generalized cross-validation score, is proposed. Random effects analysis is used to adaptively specify the structure of the penalty function based on historical samples of directly measured blood data. A collection of arterially sampled data from PET studies with FDG and H2O is used to illustrate the methodology. These data analyses are highly supportive of the overall modeling approach. An adaptation of the model to the problem of extraction of arterial blood signals from imaging data is also developed and promising preliminary results for cerebral and thoracic imaging studies with FDG and H2O are obtained.
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Affiliation(s)
- Jian Huang
- Department of Statistics, University College Cork, Ireland
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24
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Ashworth S, Berges A, Rabiner EA, Wilson AA, Comley RA, Lai RYK, Boardley R, Searle G, Gunn RN, Laruelle M, Cunningham VJ. Unexpectedly high affinity of a novel histamine H(3) receptor antagonist, GSK239512, in vivo in human brain, determined using PET. Br J Pharmacol 2014; 171:1241-9. [PMID: 24670146 PMCID: PMC3952801 DOI: 10.1111/bph.12505] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Revised: 10/23/2013] [Accepted: 10/29/2013] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE This study aimed to investigate the relationship between the plasma concentration (PK) of the novel histamine H3 receptor antagonist, GSK239512, and the brain occupancy of H(3) receptors (RO) in healthy human volunteers. EXPERIMENTAL APPROACH PET scans were obtained after i.v. administration of the H(3) -specific radioligand [(11) C]GSK189254. Each subject was scanned before and after single oral doses of GSK239512, at 4 and 24 h after dose. PET data were analysed by compartmental analysis, and regional RO estimates were obtained by graphical analysis of changes in the total volumes of distribution of the radioligand, followed by a correction for occupancy by the high affinity radioligand. The PK/RO relationship was analysed by a population-modelling approach, using the average PK of GSK239512 during each scan. KEY RESULTS Following administration of GSK239512, there was a reduction in the brain uptake of [(11) C]GSK189254 in all regions, including cerebellum. RO at 4 h was higher than at 24 h, and the PK/RO model estimated a PK associated with 50% of RO of 0.0068 ng·mL(-1) . This corresponds to a free concentration of 4.50 × 10(-12 ) M (pK = 11.3). CONCLUSIONS AND IMPLICATIONS The affinity of GSK239512 for brain H3 receptors in humans in vivo is much higher than that expected from studies in vitro, and higher than that observed in PET studies in pigs. The study illustrates the utility of carrying out PET studies in humans early in drug development, providing accurate quantification of GSK239512 RO in vivo as a function of time and dose.
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Affiliation(s)
- S Ashworth
- GlaxoSmithKline Clinical Imaging CentreLondon, UK
| | - A Berges
- GlaxoSmithKline Clinical Pharmacology Modelling & SimulationStockley Park, UK
| | - E A Rabiner
- GlaxoSmithKline Clinical Imaging CentreLondon, UK
- Department of Medicine, Imperial CollegeLondon, UK
| | - A A Wilson
- The Centre for Addiction and Mental Health (CAMH)Toronto, ON, Canada
| | - R A Comley
- GlaxoSmithKline Clinical Imaging CentreLondon, UK
| | - R Y K Lai
- GlaxoSmithKline Neurosciences Discovery MedicineHarlow, UK
| | - R Boardley
- GlaxoSmithKline Clinical Pharmacology Science & Study OperationsStevenage, UK
| | - G Searle
- GlaxoSmithKline Clinical Imaging CentreLondon, UK
| | - R N Gunn
- GlaxoSmithKline Clinical Imaging CentreLondon, UK
- Department of Medicine, Imperial CollegeLondon, UK
| | - M Laruelle
- GlaxoSmithKline Clinical Imaging CentreLondon, UK
- Department of Medicine, Imperial CollegeLondon, UK
| | - V J Cunningham
- GlaxoSmithKline Clinical Imaging CentreLondon, UK
- Department of Medicine, Imperial CollegeLondon, UK
- Aberdeen Biomedical Imaging Centre, Institute of Medical Sciences, University of AberdeenAberdeen, UK
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Malik AH, Shimazoe K, Takahashi H. Measurement of radioactivity concentration in blood by using newly developed ToT LuAG-APD based small animal PET tomograph. Annu Int Conf IEEE Eng Med Biol Soc 2013; 2013:2453-6. [PMID: 24110223 DOI: 10.1109/embc.2013.6610036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
In order to obtain plasma time activity curve (PTAC), input function for almost all quantitative PET studies, patient blood is sampled manually from the artery or vein which has various drawbacks. Recently a novel compact Time over Threshold (ToT) based Pr:LuAG-APD animal PET tomograph is developed in our laboratory which has 10% energy resolution, 4.2 ns time resolution and 1.76 mm spatial resolution. The measured value of spatial resolution shows much promise for imaging the blood vascular, i.e; artery of diameter 2.3-2.4mm, and hence, to measure PTAC for quantitative PET studies. To find the measurement time required to obtain reasonable counts for image reconstruction, the most important parameter is the sensitivity of the system. Usually small animal PET systems are characterized by using a point source in air. We used Electron Gamma Shower 5 (EGS5) code to simulate a point source at different positions inside the sensitive volume of tomograph and the axial and radial variations in the sensitivity are studied in air and phantom equivalent water cylinder. An average sensitivity difference of 34% in axial direction and 24.6% in radial direction is observed when point source is displaced inside water cylinder instead of air.
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26
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Zacho HD. Chronic intestinal ischaemia: measurement of the total splanchnic blood flow. Dan Med J 2013; 60:B4618. [PMID: 23651725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
A redundant collateral network between the intestinal arteries is present at all times. In case of ischaemia in the gastrointestinal tract, the collateral blood supply can develop further, thus accommodating the demand for oxygen even in the presence of significant stenosis or occlusion of the intestinal arteries without clinical symptoms of intestinal ischaemia. Symptoms of ischemia develop when the genuine and collateral blood supply no longer can accommodate the need for oxygen. Atherosclerosis is the most common cause of obliteration in the intestinal arteries. In chronic intestinal ischaemia (CII), the fasting splanchnic blood flow (SBF) is sufficient, but the postprandial increase in SBF is inadequate and abdominal pain will therefore develop in relation to food intake causing the patient to eat smaller meals at larger intervals with a resulting weight loss. Traditionally, the CII-diagnosis has exclusively been based upon morphology (angiography) of the intestinal arteries; however, substantial discrepancies between CII-symptoms and the presence of atherosclerosis/stenosis in the intestinal arteries have been described repeatedly in the literature impeding the diagnosis of CII. This PhD thesis explores a method to determine the total SBF and its potential use as a diagnostic tool in patients suspected to suffer from CII. The SBF can be measured using a continuous infusion of a tracer and catheterisation of a hepatic vein and an artery. By measuring the SBF before and after a standard meal it is possible to assess the ability or inability to enhance the SBF and thereby diagnosing CII. In Study I, measurement of SBF was tested against angiography in a group of patients suspected to suffer from CII due to pain and weight loss. A very good agreement between the postprandial increase in SBF and angiography was found. The method was validated against a well-established method independent of the hepatic extraction of tracer using pAH in a porcine model (study II). An excellent agreement was found between the two methods for the measurement of SBF. In the same set-up metabolism and recirculation in the intestines of the 99mTechnetium labelled tracer was rejected based on the consistency between the portal and arterial contents of tracer. Based on this study we concluded that an arterial blood sample can be used instead of a portal blood sample, making the method applicable to patients. In study III, 20 healthy volunteers and 29 patients with weight loss and abdominal pain but normal morphology of the intestinal arteries were investigated. A reference value for the meal induced SBF-increase and the relation to bodyweight was established designating that bodyweight should be taken into account when diagnosing CII based on measurement of SBF. The clinical method for measuring the SBF based on hepatic 99mTc-MBF extraction is a robust method. It allows determination of the postprandial increase in SBF providing knowledge about the circulatory physiology in intestines in patients with weight loss and abdominal pain with or without intestinal arterial stenosis. Future studies within this field could include measurement of the SBF before and after revascularisation in order to quantify the effect of revascularisation or investigate whether arterial blood sampling could be avoided or the amount of blood samples (and thus the time spend) could be reduced. The three studies were presented at eleven national and international congresses and Helle Damgaard Zacho has been awarded three prizes for the presentations.
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Affiliation(s)
- Helle D Zacho
- Department of Clinical Physiology, Viborg Hospital, Heibergs Allé 4, Viborg, Denmark.
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Zanotti-Fregonara P, Hines CS, Zoghbi SS, Liow JS, Zhang Y, Pike VW, Drevets WC, Mallinger AG, Zarate CA, Fujita M, Innis RB. Population-based input function and image-derived input function for [¹¹C](R)-rolipram PET imaging: methodology, validation and application to the study of major depressive disorder. Neuroimage 2012; 63:1532-41. [PMID: 22906792 PMCID: PMC3472081 DOI: 10.1016/j.neuroimage.2012.08.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Revised: 07/31/2012] [Accepted: 08/05/2012] [Indexed: 01/21/2023] Open
Abstract
UNLABELLED Quantitative PET studies of neuroreceptor tracers typically require that arterial input function be measured. The aim of this study was to explore the use of a population-based input function (PBIF) and an image-derived input function (IDIF) for [(11)C](R)-rolipram kinetic analysis, with the goal of reducing - and possibly eliminating - the number of arterial blood samples needed to measure parent radioligand concentrations. METHODS A PBIF was first generated using [(11)C](R)-rolipram parent time-activity curves from 12 healthy volunteers (Group 1). Both invasive (blood samples) and non-invasive (body weight, body surface area, and lean body mass) scaling methods for PBIF were tested. The scaling method that gave the best estimate of the Logan-V(T) values was then used to determine the test-retest variability of PBIF in Group 1 and then prospectively applied to another population of 25 healthy subjects (Group 2), as well as to a population of 26 patients with major depressive disorder (Group 3). Results were also compared to those obtained with an image-derived input function (IDIF) from the internal carotid artery. In some subjects, we measured arteriovenous differences in [(11)C](R)-rolipram concentration to see whether venous samples could be used instead of arterial samples. Finally, we assessed the ability of IDIF and PBIF to discriminate depressed patients (MDD) and healthy subjects. RESULTS Arterial blood-scaled PBIF gave better results than any non-invasive scaling technique. Excellent results were obtained when the blood-scaled PBIF was prospectively applied to the subjects in Group 2 (V(T) ratio 1.02±0.05; mean±SD) and Group 3 (V(T) ratio 1.03±0.04). Equally accurate results were obtained for two subpopulations of subjects drawn from Groups 2 and 3 who had very differently shaped (i.e. "flatter" or "steeper") input functions compared to PBIF (V(T) ratio 1.07±0.04 and 0.99±0.04, respectively). Results obtained via PBIF were equivalent to those obtained via IDIF (V(T) ratio 0.99±0.05 and 1.00±0.04 for healthy subjects and MDD patients, respectively). Retest variability of PBIF was equivalent to that obtained with full input function and IDIF (14.5%, 15.2%, and 14.1%, respectively). Due to [(11)C](R)-rolipram arteriovenous differences, venous samples could not be substituted for arterial samples. With both IDIF and PBIF, depressed patients had a 20% reduction in [(11)C](R)-rolipram binding as compared to control (two-way ANOVA: p=0.008 and 0.005, respectively). These results were almost equivalent to those obtained using 23 arterial samples. CONCLUSION Although some arterial samples are still necessary, both PBIF and IDIF are accurate and precise alternatives to full arterial input function for [(11)C](R)-rolipram PET studies. Both techniques give accurate results with low variability, even for clinically different groups of subjects and those with very differently shaped input functions.
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Affiliation(s)
- Paolo Zanotti-Fregonara
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Christina S. Hines
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Sami S. Zoghbi
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Jeih-San Liow
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Yi Zhang
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Victor W. Pike
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Wayne C. Drevets
- Department of Psychiatry, Oklahoma University School of Community Medicine, Oklahoma University Health Sciences Center. Tulsa. Oklahoma
| | - Alan G. Mallinger
- Experimental Therapeutics & Pathophysiology Branch, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Carlos A. Zarate
- Experimental Therapeutics & Pathophysiology Branch, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Masahiro Fujita
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
| | - Robert B. Innis
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland
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Frost ML, Siddique M, Blake GM, Moore AE, Marsden PK, Schleyer PJ, Eastell R, Fogelman I. Regional bone metabolism at the lumbar spine and hip following discontinuation of alendronate and risedronate treatment in postmenopausal women. Osteoporos Int 2012; 23:2107-16. [PMID: 21983795 DOI: 10.1007/s00198-011-1805-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2011] [Accepted: 09/27/2011] [Indexed: 10/17/2022]
Abstract
UNLABELLED The aim of this study was to examine the effects of bisphosphonate discontinuation on bone metabolism at the spine and hip measured using (18) F-fluoride PET. Bone metabolism at the spine remained stable following discontinuation of alendronate and risedronate at 1 year but increased in the hip in the alendronate group only. INTRODUCTION Bisphosphonates such as alendronate (ALN) or risedronate (RIS) have persistent effects on spine BMD following discontinuation. METHODS Positron emission tomography (PET) was used to examine regional bone metabolism in 20 postmenopausal women treated with ALN (n = 11) or RIS (n = 9) for a minimum of 3 years at screening (range 3-9 years, mean 5 years for both groups). Subjects underwent a dynamic scan of the lumbar spine and a static scan of both hips at baseline and 6 and 12 months following treatment discontinuation. (18) F-fluoride plasma clearance (K(i)) at the spine was calculated using a three-compartment model. Standardised uptake values (SUV) were calculated for the spine, total hip, femoral neck and femoral shaft. Measurements of BMD and biochemical markers of bone turnover were also performed. RESULTS With the exception of a significant decrease in spine BMD in the ALN group, BMD remained stable. Bone turnover markers increased significantly from baseline by 12 months for both study groups. Measurements of K(i) and SUV at the spine and femoral neck did not change significantly in either group. SUV at the femoral shaft and total hip increased significantly but in the ALN group only, increasing by 33.8% (p = 0.028) and 24.0% (p = 0.013), respectively. CONCLUSIONS Bone metabolism at the spine remained suppressed following treatment discontinuation. A significant increase in SUV at the femoral shaft and total hip after 12 months was observed but for the ALN group only. This study was small, and further clinical studies are required to fully evaluate the persistence of BP treatment.
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Affiliation(s)
- M L Frost
- Osteoporosis Research Unit, King's College London, Guy's Hospital Campus, Great Maze Pond, London, UK.
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De Silva RA, Jain S, Lears KA, Chong HS, Kang CS, Sun X, Rogers BE. Copper-64 radiolabeling and biological evaluation of bifunctional chelators for radiopharmaceutical development. Nucl Med Biol 2012; 39:1099-104. [PMID: 22743158 DOI: 10.1016/j.nucmedbio.2012.05.009] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Revised: 05/02/2012] [Accepted: 05/10/2012] [Indexed: 11/18/2022]
Abstract
INTRODUCTION The development of novel bifunctional chelates for attaching copper-64 to biomolecules has been an active area of research for several years. However, many of these (64)Cu-chelates have poor in vivo stability or harsh radiolabeling conditions. METHODS In this study, two triazacyclononane analogs; C-NE3TA (4-carboxymethyl-7-[2-(carboxymethyl-amino)-3-(4-nitro-phenyl)-propyl]-[1,4,7]triazo-nan-1-yl-acetic acid) and N-NE3TA (4-carboxymethyl-7-[2-[carboxymethyl-(4-nitro-benzyl)-amino]-ethyl]-[1,4,7]triazonan-1-yl-acetic acid) were evaluated for their labeling efficiency with (64)Cu at room temperature and evaluated in vitro and in vivo. In vitro studies included complexation kinetics with Cu(II) using a spectrophotometric method and rat serum stability, while the in vivo biodistribution was evaluated using SCID mice. RESULTS C-NE3TA and N-NE3TA were labeled at >95% efficiency up to ~3.4Ci/μmol. Both C-NE3TA and N-NE3TA formed complexes with Cu(II) almost immediately, with the Cu(II) complexation by C-NE3TA being faster than the formation of Cu(II)-N-NE3TA. Both (64)Cu-N-NE3TA and (64)Cu-C-NE3TA were 96.1% and 90.5% intact after 48h incubation in rat serum, respectively. This is compared to (64)Cu complexes of the control chelators, p-NH(2)-Bn-DOTA and p-NH(2)-Bn-NOTA, with 93.9% and 97.9% retention of (64)Cu in the complex, respectively. In vivo evaluation of (64)Cu-N-NE3TA and (64)Cu-C-NE3TA demonstrates good clearance from normal tissues except for the liver, where 59% and 51% of the radioactivity is retained at 24h compared to 1h for (64)Cu-N-NE3TA and (64)Cu-C-NE3TA, respectively. This compares to 78% and 3% retention for (64)Cu-p-NH(2)-Bn-DOTA and (64)Cu-p-NH(2)-Bn-NOTA. CONCLUSIONS These studies demonstrate that while N-NE3TA and C-NE3TA appear to be superior chelators for (64)Cu than p-NH(2)-Bn-DOTA, they are not better than p-NH(2)-Bn-NOTA. Nevertheless, it may still be interesting to evaluate these chelators after conjugation to biomolecules.
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Affiliation(s)
- Ravindra A De Silva
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO 63110, USA
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Willegaignon J, Sapienza MT, Buchpiguel CA. Comparison of different dosimetric methods for red marrow absorbed dose calculation in thyroid cancer therapy. Radiat Prot Dosimetry 2012; 149:138-146. [PMID: 21586539 DOI: 10.1093/rpd/ncr214] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Several dosimetric methods have been proposed for estimating red marrow absorbed dose (RMAD) when radionuclide therapy is planned for differentiated thyroid cancer, although to date, there is no consensus as to whether dose calculation should be based on blood-activity concentration or not. Our purpose was to compare RMADs derived from methods that require collecting patients' blood samples versus those involving OLINDA/EXM software, thereby precluding this invasive procedure. This is a retrospective study that included 34 patients under treatment for metastatic thyroid disease. A deviation of <10 % between RMADs was found, when comparing the doses from the most usual invasive dosimetric methods and those from OLINDA/EXM. No statistical difference between the methods was discovered, whereby the need for invasive procedures when calculating the dose is questioned. The use of OLINDA/EXM in clinical routine could possibly diminish data collection, thus giving rise to a simultaneous reduction in time and clinical costs, besides avoiding any kind of discomfort on the part of the patients involved.
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Affiliation(s)
- José Willegaignon
- Nuclear Medicine Center, Department of Radiology, School of Medicine, University of São Paulo, São Paulo, Brazil.
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Richard-Fiardo P, Franken PR, Lamit A, Marsault R, Guglielmi J, Cambien B, Graslin F, Lindenthal S, Darcourt J, Pourcher T, Vassaux G. Normalisation to blood activity is required for the accurate quantification of Na/I symporter ectopic expression by SPECT/CT in individual subjects. PLoS One 2012; 7:e34086. [PMID: 22470517 PMCID: PMC3309932 DOI: 10.1371/journal.pone.0034086] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Accepted: 02/21/2012] [Indexed: 12/21/2022] Open
Abstract
The utilisation of the Na/I symporter (NIS) and associated radiotracers as a reporter system for imaging gene expression is now reaching the clinical setting in cancer gene therapy applications. However, a formal assessment of the methodology in terms of normalisation of the data still remains to be performed, particularly in the context of the assessment of activities in individual subjects in longitudinal studies. In this context, we administered to mice a recombinant, replication-incompetent adenovirus encoding rat NIS, or a human colorectal carcinoma cell line (HT29) encoding mouse NIS. We used (99m)Tc pertechnetate as a radiotracer for SPECT/CT imaging to determine the pattern of ectopic NIS expression in longitudinal kinetic studies. Some animals of the cohort were culled and NIS expression was measured by quantitative RT-PCR and immunohistochemistry. The radioactive content of some liver biopsies was also measured ex vivo. Our results show that in longitudinal studies involving datasets taken from individual mice, the presentation of non-normalised data (activity expressed as %ID/g or %ID/cc) leads to 'noisy', and sometimes incoherent, results. This variability is due to the fact that the blood pertechnetate concentration can vary up to three-fold from day to day. Normalisation of these data with blood activities corrects for these inconsistencies. We advocate that, blood pertechnetate activity should be determined and used to normalise the activity measured in the organ/region of interest that expresses NIS ectopically. Considering that NIS imaging has already reached the clinical setting in the context of cancer gene therapy, this normalisation may be essential in order to obtain accurate and predictive information in future longitudinal clinical studies in biotherapy.
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Affiliation(s)
- Peggy Richard-Fiardo
- INSERM U948, Biothérapies Hépatiques, CHU Hôtel Dieu, Nantes, France
- CHU de Nantes, Institut des Maladies de l'Appareil Digestif, Nantes, France
| | - Philippe R. Franken
- Centre Antoine Lacassagne, Nice, France
- Faculté de Médecine, Université de Nice Sophia-Antipolis, Nice, France
- Laboratoire TIRO, UMRE 4320, iBEB, DSV, Commissariat à l'Energie Atomique, Nice, France
| | - Audrey Lamit
- Centre Antoine Lacassagne, Nice, France
- Faculté de Médecine, Université de Nice Sophia-Antipolis, Nice, France
- Laboratoire TIRO, UMRE 4320, iBEB, DSV, Commissariat à l'Energie Atomique, Nice, France
| | - Robert Marsault
- Centre Antoine Lacassagne, Nice, France
- Faculté de Médecine, Université de Nice Sophia-Antipolis, Nice, France
- Laboratoire TIRO, UMRE 4320, iBEB, DSV, Commissariat à l'Energie Atomique, Nice, France
| | - Julien Guglielmi
- Centre Antoine Lacassagne, Nice, France
- Faculté de Médecine, Université de Nice Sophia-Antipolis, Nice, France
- Laboratoire TIRO, UMRE 4320, iBEB, DSV, Commissariat à l'Energie Atomique, Nice, France
| | - Béatrice Cambien
- Centre Antoine Lacassagne, Nice, France
- Faculté de Médecine, Université de Nice Sophia-Antipolis, Nice, France
- Laboratoire TIRO, UMRE 4320, iBEB, DSV, Commissariat à l'Energie Atomique, Nice, France
| | - Fanny Graslin
- Centre Antoine Lacassagne, Nice, France
- Faculté de Médecine, Université de Nice Sophia-Antipolis, Nice, France
- Laboratoire TIRO, UMRE 4320, iBEB, DSV, Commissariat à l'Energie Atomique, Nice, France
| | - Sabine Lindenthal
- Centre Antoine Lacassagne, Nice, France
- Faculté de Médecine, Université de Nice Sophia-Antipolis, Nice, France
- Laboratoire TIRO, UMRE 4320, iBEB, DSV, Commissariat à l'Energie Atomique, Nice, France
| | - Jacques Darcourt
- Centre Antoine Lacassagne, Nice, France
- Faculté de Médecine, Université de Nice Sophia-Antipolis, Nice, France
- Laboratoire TIRO, UMRE 4320, iBEB, DSV, Commissariat à l'Energie Atomique, Nice, France
| | - Thierry Pourcher
- Centre Antoine Lacassagne, Nice, France
- Faculté de Médecine, Université de Nice Sophia-Antipolis, Nice, France
- Laboratoire TIRO, UMRE 4320, iBEB, DSV, Commissariat à l'Energie Atomique, Nice, France
| | - Georges Vassaux
- INSERM U948, Biothérapies Hépatiques, CHU Hôtel Dieu, Nantes, France
- CHU de Nantes, Institut des Maladies de l'Appareil Digestif, Nantes, France
- * E-mail:
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Zeevaart JR, Louw WKA, Kolar ZI, Kilian E, van Rensburg FEJ, Dormehl IC. Biodistribution and Pharmacokinetics of Variously Molecular Sized 117mSn(II)-Polyethyleneiminomethyl Phosphonate Complexes in the Normal Primate Model as Potential Selective Therapeutic Bone Agents. Arzneimittelforschung 2011; 54:340-7. [PMID: 15281620 DOI: 10.1055/s-0031-1296981] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
In the search for a cure for metastatic bone cancer, 117mSn with its conversion electrons and low energy photons both of discrete energies shows little bone marrow toxicity, providing the opportunity to increase the administered dose. Selective accumulation in lesions would capitalise on this advantage. The 10-30 kDa fraction of the water-soluble polymer polyethyleneimine, functionalised with methyl phosphonate groups (PEI-MP) and labelled with 99mTc, has shown selective uptake into bone tumours. Furthermore using speciation calculations it was predicted that the Sn(II)-PEI-MP complex would remain intact in the blood plasma. Because of this positive indication animal experiments were carried out to test this prediction. This paper relates the labelling, biodistribution and pharmacokinetics of various fractions of 117mSn-(II) PEI-MP in the normal primate model, and points to promising therapeutic possibilities.
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Affiliation(s)
- Jan R Zeevaart
- Radiochemistry, South African Nuclear Energy Corporation (NECSA), Pretoria, South Africa.
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Saatchi K, Gelder N, Gershkovich P, Sivak O, Wasan KM, Kainthan RK, Brooks DE, Häfeli UO. Long-circulating non-toxic blood pool imaging agent based on hyperbranched polyglycerols. Int J Pharm 2011; 422:418-27. [PMID: 22044540 DOI: 10.1016/j.ijpharm.2011.10.036] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2011] [Revised: 10/04/2011] [Accepted: 10/18/2011] [Indexed: 11/17/2022]
Abstract
PURPOSE Currently, in vivo or in vitro(99m)Tc-radiolabelled red blood cells are the standard blood pool imaging agents. Due to risks associated with handling of blood and the problems with the current (99m)Tc shortage, we were interested in a long-circulating biocompatible synthetic macromolecule that would be simple to prepare and could also be used for PET imaging. METHODS A high molecular weight hyperbranched polyglycerol (HPG) of 500 kDa was derivatized to coordinate radioactive gallium and to establish its labelling efficiency, stability and pharmacokinetics. RESULTS The resulting radiopharmaceutical in kit form was labelled rapidly within a couple of minutes at room temperature, was stable in transferrin and EDTA challenge tests, and was non-toxic in both cell viability and different hemocompatibility assays. A pharmacokinetic biodistribution study showed that the (67)Ga-HPGN was confined to the blood compartment with a biological half life of 50.7h. CONCLUSION (67)Ga-HPGN is thus a simple to prepare blood pool imaging agent for applications where a long biological half-life is essential, i.e., the diagnosis of internal bleeding. Since radiolabelling of the same kit with (68)Ga was also confirmed, we plan to evaluate it shortly as a PET blood pool imaging agent for cardiac applications.
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Affiliation(s)
- Katayoun Saatchi
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
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Souza DE, Pereira MO, Bernardo LC, Carmo FS, Fonseca ADSD, Bernardo-Filho M. An experimental model to study the effects of a senna extract on the blood constituent labeling and biodistribution of a radiopharmaceutical in rats. Clinics (Sao Paulo) 2011; 66:483-6. [PMID: 21552677 PMCID: PMC3072012 DOI: 10.1590/s1807-59322011000300021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2010] [Accepted: 11/26/2010] [Indexed: 11/21/2022] Open
Abstract
Cassia angustifolia Vahl (senna) is a natural product that contains sennosides, which are active components that affect the intestinal tract and induce diarrhea. Authors have shown that senna produces DNA (deoxyribonucleic acid) lesions in Escherichia coli cultures and can act as an antifungal agent. Natural drugs can alter the labeling of blood constituents with technetium-⁹⁹m (⁹⁹mTc) and can affect the biodistribution of radiopharmaceuticals. In this work, we have evaluated the influence of a senna extract on the radiolabeling of blood constituents and on the biodistribution of the radiopharmaceutical sodium pertechnetate (Na⁹⁹mTcO₄)in Wistar rats. Twelve animals were treated with senna extract for 7 days. Blood samples were withdrawn from the animals and the radiolabeling procedure was carried out. The senna extract did not modify the radiolabeling of the blood constituents. A biodistributional assay was performed by administering Na⁹⁹mTcO₄ and determining its activity in different organs and in blood. The senna extract altered the biodistribution of Na⁹⁹mTcO₄ in the thyroid, liver, pancreas, lungs and blood. These results are associated with properties of the chemical substances present in the aqueous senna extract. Although these assays were performed in animals, our findings suggest that caution should be exercised when nuclear medicine examinations using Na⁹⁹mTcO₄ are conducted in patients who are using senna extract.
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Affiliation(s)
- Deise Elizabeth Souza
- Laboratório de Radiofarmácia Experimental, Departamento de Biofísica e Biometria, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Brazil
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Liu IH, Chang CH, Ho CL, Chiu SP, Lee WC, Chang TJ, Chen LC, Wu YH, Chuang CH, Fu YK, Lee TW. Multimodality imaging and preclinical evaluation of 177Lu-AMBA for human prostate tumours in a murine model. Anticancer Res 2010; 30:4039-4048. [PMID: 21036718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
AMBA (DO3A-CH(2)CO-G-(4-aminobenzoyl)-QWAVGHLM-NH(2)) is a bombesin (BN)-like peptide having high affinity with gastrin-releasing peptide receptors (GRPr).(177)Lu-AMBA is currently undergoing clinical trial as a systemic radiotherapy for hormone refractory prostate cancer (HRPC) patients. This study evaluated the biodistribution, pharmacokinetics, bioluminescent imaging (BLI) and microSPECT/CT imaging of (177)Lu-AMBA in PC-3M-luc-C6 luciferase-expressing human prostate tumour-bearing mice. Plasma stability of (177)Lu-AMBA could be maintained up to 55.67±6.07% at 24 h in a protection buffer. High positive correlations of PC-3M luc-C6 tumour growth in SCID mice between caliper measurement and BLI were observed (R(2)=0.999). Both the biodistribution and microSPECT/CT imaging in PC-3M-luc-C6 bearing-tumour mice showed that (177)Lu-AMBA in tumour uptake could be retained for 24 h. The distribution half-life (t(1/2α)) and the elimination half-life (t(1/2β)) of (177) Lu-AMBA in mice were 0.52 h and 26.6 h, respectively. These results indicated that BLI could be used to monitor the growth of tumour. High uptake of (177)Lu-AMBA in PC-3M-luc-C6 tumour-bearing mice by microSPECT/CT imaging can further evaluate the potential of (177)Lu-AMBA therapy for PC-3M-luc-C6 tumours.
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Affiliation(s)
- I-Hsiang Liu
- Institute of Nuclear Energy Research, Taoyuan, Taiwan, ROC
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Wesolowski CA, Puetter RC, Ling L, Babyn PS. Tikhonov adaptively regularized gamma variate fitting to assess plasma clearance of inert renal markers. J Pharmacokinet Pharmacodyn 2010; 37:435-74. [PMID: 20865304 PMCID: PMC2953622 DOI: 10.1007/s10928-010-9167-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2010] [Accepted: 09/02/2010] [Indexed: 11/26/2022]
Abstract
The Tk-GV model fits Gamma Variates (GV) to data by Tikhonov regularization (Tk) with shrinkage constant, λ, chosen to minimize the relative error in plasma clearance, CL (ml/min). Using (169)Yb-DTPA and (99m)Tc-DTPA (n = 46, 8-9 samples, 5-240 min) bolus-dilution curves, results were obtained for fit methods: (1) Ordinary Least Squares (OLS) one and two exponential term (E₁ and E₂), (2) OLS-GV and (3) Tk-GV. Four tests examined the fit results for: (1) physicality of ranges of model parameters, (2) effects on parameter values when different data subsets are fit, (3) characterization of residuals, and (4) extrapolative error and agreement with published correction factors. Test 1 showed physical Tk-GV results, where OLS-GV fits sometimes-produced nonphysical CL. Test 2 showed the Tk-GV model produced good results with 4 or more samples drawn between 10 and 240 min. Test 3 showed that E₁ and E₂ failed goodness-of-fit testing whereas GV fits for t > 20 min were acceptably good. Test 4 showed CL(Tk-GV) clearance values agreed with published CL corrections with the general result that CL(E1) > CL(E2) > CL(Tk-GV) and finally that CL(Tk-GV) were considerably more robust, precise and accurate than CL(E2), and should replace the use of CL(E2) for these renal markers.
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Affiliation(s)
- Carl A Wesolowski
- Nuclear Medicine, The General Hospital, HSC, 300 Prince Philip Drive, St. John's, NF A1B 3V6, Canada.
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Tantawy MN, Peterson TE. Simplified [18F]FDG image-derived input function using the left ventricle, liver, and one venous blood sample. Mol Imaging 2010; 9:76-86. [PMID: 20236605 PMCID: PMC4095848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023] Open
Abstract
A relatively simple, almost entirely noninvasive imaging-based method is presented for deriving arterial blood input functions for quantitative [(18)F]2-fluoro-2-deoxy-d-glucose (FDG) positron emission tomographic (PET) studies in rodents. It requires only one venous blood sample at the end of the scan. MicroPET images and arterial blood time-activity curves (TACs) were downloaded from the Mouse Quantitation Program database at the University of California, Los Angeles. Three-dimensional regions of interest were drawn around the blood-pool region of the left ventricle and within the liver to derive their respective TACs. To construct the "hybrid" image-derived input function (IDIF), the initial part of the left ventricle TAC, containing the peak concentration of [(18)F]FDG in the arterial blood, was corrected for spillout (ie, partial-volume effect yielding a recovery coefficient < 1) and then joined to the liver TAC (normalized to the 60-minute arterial blood sample) immediately after it peaks. To validate our method, the [(18)F]FDG influx constant (K(i)) was estimated using a two-tissue compartment model and compared to estimates of K(i) obtained using measured arterial blood TACs. No significant difference in the K(i) estimates was obtained with the arterial blood input function and our hybrid IDIF. We conclude that the normalized hybrid IDIF can be used in practice to obtain reliable K(i) estimates.
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Affiliation(s)
- Mohammed Noor Tantawy
- Department of Radiology and Radiological Sciences, Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN, USA
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Muftuler FZB, Unak P, Yolcular S, Kilcar AY, Ichedef C, Enginar H, Sakarya S. Synthesis, radiolabeling and In Vivo tissue distribution of an anti-oestrogen glucuronide compound, (99m)Tc-TOR-G. Anticancer Res 2010; 30:1243-1249. [PMID: 20530435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Toremifene (TOR) has been used as an anti-oestrogen drug for the treatment and prevention of human breast cancer. The aim of this study was the addition of the hydrophilic groups diethylenetriamine pentaacetic acid (DTPA) and glucuronic acid to the starting substance TOR and to label it with technetium-99m ((99m)Tc) radionuclide and to investigate radiopharmaceutical potential of the new compound. The synthesis reactions are completed in four steps, including enzymatic reaction, with the following substeps; preparation of microsomal fraction from Hutu 80 cell line and subsequent purification of UDP-glucuronyl transferase (UDPGT), estimation of protein quantity in microsomal samples and glucuronidation reaction. The results indicate that (99m)Tc-TOR-G may be proposed as a new anti-oestrogen glucuronide imaging agent for ovarian tumours.
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Affiliation(s)
- F Z Biber Muftuler
- Department of Nuclear Applications, Institute of Nuclear Sciences, Ege University, Izmir, Turkey.
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Muftuler FZB, Unak P, Teksoz S, Acar C, Yolcular S, Yürekli Y. 131I labeling of tamoxifen and biodistribution studies in rats. Appl Radiat Isot 2008; 66:178-87. [PMID: 17888670 DOI: 10.1016/j.apradiso.2007.08.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2007] [Revised: 06/11/2007] [Accepted: 08/06/2007] [Indexed: 11/15/2022]
Abstract
Tamoxifen [TAM ([Z]-2-[4-(1,2-diphenyl-1-di-butenyl)-phenoxy]-N,N-dimethylethanamine)] has been used as an antiestrogen drug for treatment and prevention of human breast cancer. Tamoxifen was labeled with 131I using iodogen as an oxidizing agent. Mass spectroscopy of the cold standard showed that the labeling occurs in ortho position to the phenyl ether position of TAM as expected. Quality control, radiochemical yield and stability were established using the radioelectrophoresis method. The radiolabeled compound maintained its stability throughout working period of 24 h. Scintigraphic imaging was performed and tissue distribution was determined in Albino Wistar rats. According to biodistribution and imaging experiments the radiolabeled compound presented estrogen receptor (ER) specificity and it was uptaken by endometrium as well as breast tissue.
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Affiliation(s)
- F Z Biber Muftuler
- Department of Nuclear Applications, Institute of Nuclear Sciences, Ege University, Bornova-Izmir, Turkey.
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Logan J, Alexoff D, Kriplani A. Simplifications in analyzing positron emission tomography data: effects on outcome measures. Nucl Med Biol 2007; 34:743-56. [PMID: 17921027 DOI: 10.1016/j.nucmedbio.2007.06.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2007] [Revised: 05/25/2007] [Accepted: 06/06/2007] [Indexed: 11/19/2022]
Abstract
Initial validation studies of new radiotracers generally involve kinetic models that require a measured arterial input function. This allows for the separation of tissue binding from delivery and blood flow effects. However, when using a tracer in a clinical setting, it is necessary to eliminate arterial blood sampling due to its invasiveness and the extra burden of counting and analyzing the blood samples for metabolites. In some cases, it may also be necessary to replace dynamic scanning with a shortened scanning period some time after tracer injection, as is done with FDG (F-18 fluorodeoxyglucose). These approximations represent loss of information. In this work, we considered several questions related to this: (1) Do differences in experimental conditions (drug treatments) or populations affect the input function, and what effect, if any, does this have on the final outcome measure? (2) How do errors in metabolite measurements enter into results? (3) What errors are incurred if the uptake ratio is used in place of the distribution volume ratio? (4) Is one- or two-point blood sampling any better for FDG data than the standardized uptake value? and (5) If blood sampling is necessary, what alternatives are there to arterial blood sampling? The first three questions were considered in terms of data from human dynamic positron emission tomography (PET) studies under conditions of baseline and drug pretreatment. Data from [11C]raclopride studies and those from the norepinephrine transporter tracer (S,S)-[11C]O-methyl reboxetine were used. Calculation of a metabolic rate for FDG using the operational equation requires a measured input function. We tested a procedure based on two blood samples to estimate the plasma integral and convolution that occur in the operational equation. There are some tracers for which blood sampling is necessary. Strategies for brain studies involve using the internal carotids in estimating the radioactivity after correcting for partial volume and spillover in order to eliminate arterial sampling. Some venous blood samples are still required for metabolite measurements. The ultimate solution to the problem of arterial sampling may be a wrist scanner, which acts as a small PET camera for imaging the arteries in the wrist. This is currently under development.
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Affiliation(s)
- Jean Logan
- Medical Department, Brookhaven National Laboratory, Upton, NY 11973, USA.
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Toft KG, Johnson JA, Oulie I, Skotland T. NC100668, a New Tracer Tested for Imaging of Venous Thromboembolism: Pharmacokinetics and Metabolism in Humans. Drug Metab Dispos 2007; 35:1979-84. [PMID: 17682073 DOI: 10.1124/dmd.106.014126] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The (99m)Tc-complex of NC100668 [Acetyl-Asn-Gln-Glu-Gln-Val-Ser-Pro-Tyr(3-iodo)-Thr-Leu-Leu-Lys-Gly-NC100194] is a new tracer tested for nuclear medical imaging of venous thromboembolism. NC100668 is a 13-amino acid peptide with a Tc-binding chelator [NC100194; -NH-CH2-CH2-N(CH2-CH2-NH-C(CH3)2-C(CH3)=N-OH)2] linked to the C-terminal end. The present study was performed following injection of (99m)Tc-NC100668 in healthy human volunteers with five dose levels of NC100668 (20-2000 microg) and a constant radioactivity dose. The rate at which the radioactivity was cleared from blood was independent of gender and dose of NC100668; more than half of the 82% urinary clearance of radioactivity was obtained 2 h postinjection. The radioactivity in blood was reduced to 50% of initial values within 12 min; this was followed by a more gradual decrease with a half-life of 1.2 h and a terminal elimination half-life of 10.5 h. The plasma concentration of NC100668 decreased rapidly with an initial half-life of 5 to 10 min. The half-life after this initial phase could be estimated for only two of the subjects in the highest-dose group because the NC100668 concentration in the other samples at these time points was below the limit of detection of the liquid chromatography/mass spectrometry (LC/MS) method. LC/MS analyses of urine samples revealed the identity of two metabolites generated from the C-terminal end of the molecule; Gly-NC100194 was identified as the major metabolite and NC100194 as a minor metabolite. The estimated sum of these two metabolites is in the same magnitude as the recoveries of (99m)Tc in these samples, indicating that most of the (99m)Tc excreted in urine is bound to one of these metabolites.
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Affiliation(s)
- Kim G Toft
- Research and Development, GE Healthcare, Nycoveien 2, N-0401 Oslo, Norway.
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Shumway DA, Pavlova OA, Mukhin AG. A simplified method for the measurement of nonmetabolized 2-[18F]F-A-85380 in blood plasma using solid-phase extraction. Nucl Med Biol 2007; 34:221-8. [PMID: 17307130 DOI: 10.1016/j.nucmedbio.2006.12.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2006] [Revised: 11/02/2006] [Accepted: 12/05/2006] [Indexed: 11/29/2022]
Abstract
Quantification of alpha(4)beta(2)* nicotinic acetylcholine receptors using 2-[(18)F]fluoro-3-(2(S)-azetidinylmethoxy)pyridine (2-[(18)F]FA) and positron emission tomography (PET) imaging requires measurement of nonmetabolized radioligand in blood plasma, which was previously accomplished using high-performance liquid chromatography (HPLC). Here, we introduce a one-step solid-phase extraction (SPE) method for measuring the concentration of nonmetabolized 2-[(18)F]FA. This method allows many samples to be processed in a short period of time. SPE effectively separated 2-[(18)F]FA from radioactive metabolites typically observed in blood plasma after administration of radioligand in humans. Measurements of the 2-[(18)F]FA parent fraction in healthy human volunteers obtained using the SPE method were nearly identical to those obtained using HPLC (1.3+/-5% average underestimation of SPE), and reproducibility was good within and between runs (2% and 6% coefficient of variation, respectively). SPE recovery of 2-[(18)F]FA from blood plasma was not appreciably diminished (3+/-0.6%) by a larger volume of blood plasma loaded onto the cartridge, suggesting the possibility of increasing the plasma sample volume at later times in a PET study to improve measurement sensitivity. 2-[(18)F]FA was stable in blood stored on ice over 8 h and in saline at low concentrations (<2 MBq/ml) but not at high concentrations (ca. 130 MBq/ml). Using SPE, the elimination half-life and full body distribution volume of 2-[(18)F]FA in healthy human volunteers were estimated as 4.2+/-0.8 h and 220+/-70 L, respectively. These results suggest that SPE is the method of choice for the determination of the plasma 2-[(18)F]FA concentration when measurement of individual metabolites is not required.
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Affiliation(s)
- Dean A Shumway
- Neuroimaging Research Branch, National Institute on Drug Abuse, Intramural Research Program, NIH, DHHS, Baltimore, MD 21224, USA
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Marik J, Tartis MS, Zhang H, Fung JY, Kheirolomoom A, Sutcliffe JL, Ferrara KW. Long-circulating liposomes radiolabeled with [18F]fluorodipalmitin ([18F]FDP). Nucl Med Biol 2007; 34:165-71. [PMID: 17307124 PMCID: PMC1849971 DOI: 10.1016/j.nucmedbio.2006.12.004] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2006] [Revised: 11/30/2006] [Accepted: 12/05/2006] [Indexed: 12/11/2022]
Abstract
Synthesis of a radiolabeled diglyceride, 3-[(18)F]fluoro-1,2-dipalmitoylglycerol [[(18)F]fluorodipalmitin ([(18)F]FDP)], and its potential as a reagent for radiolabeling long-circulating liposomes were investigated. The incorporation of (18)F into the lipid molecule was accomplished by nucleophilic substitution of the p-toluenesulfonyl moiety with a decay-corrected yield of 43+/-10% (n=12). Radiolabeled, long-circulating polyethylene-glycol-coated liposomes were prepared using a mixture of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine, cholesterol, 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethyleneglycol)-2000] ammonium salt (61:30:9) and [(18)F]FDP with a decay-corrected yield of 70+/-8% (n=4). PET imaging and biodistribution studies were performed with free [(18)F]FDP and liposome-incorporated [(18)F]FDP. Freely injected [(18)F]FDP had the highest uptake in the liver, spleen and lungs. Liposomal [(18)F]FDP remained in blood circulation at near-constant levels for at least 90 min, with a peak concentration near 2.5%ID/cc. Since [(18)F]FDP was incorporated into the phospholipid bilayer, it could potentially be used for radiolabeling a variety of lipid-based drug carriers.
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Affiliation(s)
| | | | | | | | | | | | - Katherine W. Ferrara
- Corresponding Author: Katherine W. Ferrara, Department of Biomedical Engineering, 451 East Health Sciences Drive, University of California, Davis, Davis, CA 95616-5294, Tel: 530 754-9436, Fax: 530 754-5739,
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Logan J, Wang GJ, Telang F, Fowler JS, Alexoff D, Zabroski J, Jayne M, Hubbard B, King P, Carter P, Shea C, Xu Y, Muench L, Schlyer D, Learned-Coughlin S, Cosson V, Volkow ND, Ding YS. Imaging the norepinephrine transporter in humans with (S,S)-[11C]O-methyl reboxetine and PET: problems and progress. Nucl Med Biol 2007; 34:667-79. [PMID: 17707807 DOI: 10.1016/j.nucmedbio.2007.03.013] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2007] [Revised: 03/03/2007] [Accepted: 03/27/2007] [Indexed: 11/22/2022]
Abstract
UNLABELLED Results from human studies with the PET radiotracer (S,S)-[(11)C]O-methyl reboxetine ([(11)C](S,S)-MRB), a ligand targeting the norepinephrine transporter (NET), are reported. Quantification methods were determined from test/retest studies, and sensitivity to pharmacological blockade was tested with different doses of atomoxetine (ATX), a drug that binds to the NET with high affinity (K(i)=2-5 nM). METHODS Twenty-four male subjects were divided into different groups for serial 90-min PET studies with [(11)C](S,S)-MRB to assess reproducibility and the effect of blocking with different doses of ATX (25, 50 and 100 mg, po). Region-of-interest uptake data and arterial plasma input were analyzed for the distribution volume (DV). Images were normalized to a template, and average parametric images for each group were formed. RESULTS [(11)C](S,S)-MRB uptake was highest in the thalamus (THL) and the midbrain (MBR) [containing the locus coeruleus (LC)] and lowest for the caudate nucleus (CDT). The CDT, a region with low NET, showed the smallest change on ATX treatment and was used as a reference region for the DV ratio (DVR). The baseline average DVR was 1.48 for both the THL and MBR with lower values for other regions [cerebellum (CB), 1.09; cingulate gyrus (CNG) 1.07]. However, more accurate information about relative densities came from the blocking studies. MBR exhibited greater blocking than THL, indicating a transporter density approximately 40% greater than THL. No relationship was found between DVR change and plasma ATX level. Although the higher dose tended to induce a greater decrease than the lower dose for MBR (average decrease for 25 mg=24+/-7%; 100 mg=31+/-11%), these differences were not significant. The different blocking between MBR (average decrease=28+/-10%) and THL (average decrease=17+/-10%) given the same baseline DVR indicates that the CDT is not a good measure for non-NET binding in both regions. Threshold analysis of the difference between the average baseline DV image and the average blocked image showed the expected NET distribution with the MBR (LC) and hypothalamus>THL>CNG and CB, as well as a significant change in the supplementary motor area. DVR reproducibility for the different brain regions was approximately 10%, but intersubject variability was large. CONCLUSIONS The highest density of NETs was found in the MBR where the LC is located, followed by THL, whereas the lowest density was found in basal ganglia (lowest in CDT), consistent with the regional localization of NETs in the nonhuman primate brain. While all three doses of ATX were found to block most regions, no significant differences between doses were found for any region, although the average percent change across subjects of the MBR did correlate with ATX dose. The lack of a dose effect could reflect a low signal-to-noise ratio coupled with the possibility that a sufficient number of transporters were blocked at the lowest dose and further differences could not be detected. However, since the lowest (25 mg) dose is less than the therapeutic doses used in children for the treatment of attention-deficit/hyperactivity disorder ( approximately 1.0 mg/kg/day), this would suggest that there may be additional targets for ATX's therapeutic actions.
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Affiliation(s)
- Jean Logan
- Medical Department, Brookhaven National Laboratory, Upton, NY 11973, USA.
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Abstract
UNLABELLED Many quantitative imaging protocols that make use of a metabolite-corrected arterial input function require the use of a mathematic model to describe the rate of metabolism of the radioligand. Commonly, parametric models are fit to metabolism data and then the fitted model is used to correct the plasma input function. (11)C-WAY 100635 is a rapidly metabolized radioligand used extensively in mapping the 5-hydroxytryptamine receptor 1A system. METHODS To evaluate the adequacy of fit of 4 metabolite models, we examined data from 92 subjects who received an injection of (11)C-WAY 100635, were imaged with PET, and underwent measurement of total plasma concentration and metabolites. The performance of these models was assessed according to residual plots, as well as fit and information criteria. RESULTS The study showed that the choice of model has a substantial effect on the resulting estimates of outcome measures. CONCLUSION Among the models considered, the Hill model provides the best fit across all criteria.
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Affiliation(s)
- Songmei Wu
- New York City Department of Health and Mental Hygiene, New York, New York, USA
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Schuitemaker A, van Berckel BNM, Kropholler MA, Veltman DJ, Scheltens P, Jonker C, Lammertsma AA, Boellaard R. SPM analysis of parametric (R)-[11C]PK11195 binding images: Plasma input versus reference tissue parametric methods. Neuroimage 2007; 35:1473-9. [PMID: 17363280 DOI: 10.1016/j.neuroimage.2007.02.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2006] [Revised: 02/08/2007] [Accepted: 02/08/2007] [Indexed: 11/26/2022] Open
Abstract
(R)-[11C]PK11195 has been used for quantifying cerebral microglial activation in vivo. In previous studies, both plasma input and reference tissue methods have been used, usually in combination with a region of interest (ROI) approach. Definition of ROIs, however, can be labourious and prone to interobserver variation. In addition, results are only obtained for predefined areas and (unexpected) signals in undefined areas may be missed. On the other hand, standard pharmacokinetic models are too sensitive to noise to calculate (R)-[11C]PK11195 binding on a voxel-by-voxel basis. Linearised versions of both plasma input and reference tissue models have been described, and these are more suitable for parametric imaging. The purpose of this study was to compare the performance of these plasma input and reference tissue parametric methods on the outcome of statistical parametric mapping (SPM) analysis of (R)-[11C]PK11195 binding. Dynamic (R)-[11C]PK11195 PET scans with arterial blood sampling were performed in 7 younger and 11 elderly healthy subjects. Parametric images of volume of distribution (Vd) and binding potential (BP) were generated using linearised versions of plasma input (Logan) and reference tissue (Reference Parametric Mapping) models. Images were compared at the group level using SPM with a two-sample t-test per voxel, both with and without proportional scaling. Parametric BP images without scaling provided the most sensitive framework for determining differences in (R)-[11C]PK11195 binding between younger and elderly subjects. Vd images could only demonstrate differences in (R)-[11C]PK11195 binding when analysed with proportional scaling due to intersubject variation in K1/k2 (blood-brain barrier transport and non-specific binding).
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Affiliation(s)
- Alie Schuitemaker
- Department of Nuclear Medicine and PET Research, VU University Medical Centre, P.O. Box 7057, 1081 MB Amsterdam, The Netherlands
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Liberatore M, Al-Nahhas A, Rubello D. White blood cell scan in the follow-up of infectious diseases: is the withdrawal of antibiotic therapy necessary? Nucl Med Commun 2007; 28:151-3. [PMID: 17264771 DOI: 10.1097/mnm.0b013e328054c56a] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Haugbøl S, Pinborg LH, Regeur L, Hansen ES, Bolwig TG, Nielsen FA, Svarer C, Skovgaard LT, Knudsen GM. Cerebral 5-HT2A receptor binding is increased in patients with Tourette's syndrome. Int J Neuropsychopharmacol 2007; 10:245-52. [PMID: 16945163 DOI: 10.1017/s1461145706006559] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2005] [Revised: 01/06/2006] [Accepted: 01/12/2006] [Indexed: 11/07/2022] Open
Abstract
Experimental and clinical data have suggested that abnormalities in the serotonergic neurotransmissions in frontal-subcortical circuits are involved in Tourette's syndrome. To test the hypothesis that the brain's 5-HT2A receptor binding is increased in patients with Tourette's syndrome, PET imaging was performed. Twenty adults with Tourette's syndrome and 20 healthy control subjects were investigated with PET-[18F]altanserin using a bolus-infusion protocol. Regions of interest were delineated automatically on co-registered MRI images, and partial volume-corrected binding parameters were extracted from the PET images. Comparison between control subjects and Tourette's syndrome patients showed increased specific [18F]altanserin binding, not only in the a-priori selected brain regions hypothesized to be involved in Tourette's syndrome, but also post-hoc analysis showed a global up-regulation when testing for a overall difference with a randomization test (p<0.03). Increased 5-HT2A receptor binding was found not only in regions closely related to subcortical regions in patients with Tourette's syndrome, but also in most other brain regions. Our data suggest that the serotonergic transmitter system is pathophysiologically involved in Tourette's syndrome and that a clinical trial with 5-HT2A receptor antagonists may be justified.
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Affiliation(s)
- Steven Haugbøl
- Neurobiology Research Unit, Copenhagen University Hospital, Denmark.
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Palma E, Oliveira BL, Correia JDG, Gano L, Maria L, Santos IC, Santos I. A new bisphosphonate-containing 99mTc(I) tricarbonyl complex potentially useful as bone-seeking agent: synthesis and biological evaluation. J Biol Inorg Chem 2007; 12:667-79. [PMID: 17333301 DOI: 10.1007/s00775-007-0215-0] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2006] [Accepted: 01/28/2007] [Indexed: 10/23/2022]
Abstract
Aiming to develop new bone-seeking radiotracers based on the organometallic core fac-[(99m)Tc(CO)(3)](+) with improved radiochemical and biological properties, we have prepared new conjugates with phosphonate pendant groups. The conjugates comprise a chelating unit for metal coordination, which corresponds to a pyrazolyl-containing backbone (pz) with a N,N,N donor-atom set, and a pendant diethyl phosphonate (pz-MPOEt), phosphonic acid (pz-MPOH) or a bisphosphonic acid (pz-BPOH) group for bone targeting. Reactions of the conjugates with the precursor [(99m)Tc(H(2)O)(3)(CO)(3)](+) yielded (mote than 95%) the single and well-defined radioactive species [(99m)Tc(CO)(3)(kappa(3)-pz-MPOEt)](+) (1a), [(99m)Tc(CO)(3)(kappa(3)-pz-MPOH](+) (2a) and [(99m)Tc(CO)(3)(kappa(3)-pz-BPOH)](+) (3a), which were characterized by reversed-phase high-performance liquid chromatography . The corresponding Re surrogates (1-3), characterized by the usual analytical techniques, including X-ray diffraction analysis in the case of 1, allowed for macroscopic identification of the radioactive conjugates. These radioactive complexes revealed high stability both in vitro (phosphate-buffered saline solution and human plasma) and in vivo, without any measurable decomposition. Biodistribution studies of the complexes in mice indicated a fast rate of blood clearance and high rate of total radioactivity excretion, occurring primarily through the renal-urinary pathway in the case of complex 3a. Despite presenting moderate bone uptake (3.04 +/- 0.47% injected dose per gram of organ, 4 h after injection), the high stability presented by 3a and its adequate in vivo pharmacokinetics encourages the search for new ligands with the same chelating unit and different bisphosphonic acid pendant arms.
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Affiliation(s)
- Elisa Palma
- Departamento de Química, ITN, Estrada Nacional 10, 2686-953 Sacavém Codex, Portugal
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Montgomery AJ, Asselin MC, Farde L, Grasby PM. Measurement of methylphenidate-induced change in extrastriatal dopamine concentration using [11C]FLB 457 PET. J Cereb Blood Flow Metab 2007; 27:369-77. [PMID: 16685253 DOI: 10.1038/sj.jcbfm.9600339] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
[(11)C]FLB 457 is a very high-affinity radiotracer that allows the measurement of dopamine D(2/3) receptor availability in regions of the brain where densities are very low, such as the cerebral cortex. It is not known if [(11)C]FLB 457 binding is sensitive to the concentration of endogenous dopamine in humans in a manner analogous to [(11)C]raclopride and [(123)I]IBZM in the striatum. To test this possibility, extrastriatal [(11)C]FLB 457 binding was measured at baseline and after the oral administration of 40 to 60 mg of the psychostimulant methylphenidate (MP) in 12 healthy volunteers using positron emission tomography (PET) in a balanced-order, double-blind design. The dynamic PET data were quantified using a two-tissue compartment model with a metabolite-corrected arterial plasma input function. Two volunteers were excluded because of excessive head movement. In the remainder, MP caused significant reductions in the volume of distribution (VD) in temporal and frontal cortical regions and thalamus, suggesting that [(11)C]FLB 457 binding is sensitive to endogenous dopamine concentration. Moreover, the change in [(11)C]FLB 457 binding after MP correlated with the dose of MP (in mg/kg body weight) in all regions assessed. We conclude that MP in doses within the therapeutic range for the treatment of attention deficit hyperactivity disorder causes increases in dopamine concentrations in extrastriatal regions and that [(11)C]FLB 457 PET may be a useful tool for the assessment of change in dopamine concentration in these areas in humans.
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Affiliation(s)
- Andrew J Montgomery
- MRC Clinical Sciences Centre, Cyclotron Building, Imperial College, Hammersmith Hospital, London, UK.
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