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Parvizi T, Wurm R, König T, Silvaieh S, Altmann P, Klotz S, Regelsberger G, Traub‐Weidinger T, Gelpi E, Stögmann E. Real-world performance of plasma p-tau181 in a heterogeneous memory clinic cohort. Ann Clin Transl Neurol 2024; 11:1988-1998. [PMID: 38965832 PMCID: PMC11330220 DOI: 10.1002/acn3.52116] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Revised: 04/22/2024] [Accepted: 05/23/2024] [Indexed: 07/06/2024] Open
Abstract
OBJECTIVE In light of clinical trials and disease-modifying therapies, an early identification of patients at-risk of developing Alzheimer's disease (AD) is crucial. Blood-based biomarkers have shown promising results regarding the in vivo detection of the earliest neuropathological changes in AD. Herein, we investigated the ability of plasma p-tau181 to act as a prescreening marker for amyloid positivity in a heterogeneous memory clinic-based cohort. METHODS In this retrospective cross-sectional study, we included a total of 115 patients along the clinical AD continuum (mild cognitive impairment [MCI] due to AD, n = 62, probable AD dementia, n = 53). Based on their biomarker status, they were stratified into an amyloid-positive (Aβ+, n = 88) or amyloid-negative cohort (Aβ-, n = 27). Plasma and CSF p-tau181 concentrations were quantified using an ultrasensitive single-molecule array (SIMOA©). Furthermore, age- and sex-adjusted receiver operating characteristic (ROC) curves were calculated and the area under the curve (AUC) of each model was compared using DeLong's test for correlated AUC curves. RESULTS The median (interquartile range [IQR]) concentration of plasma p-tau181 was significantly higher in Aβ+ patients (3.6 pg/mL [2.5-4.6]), compared with Aβ- patients (1.7 pg/mL [1.2-1.9], p < 0.001). Regarding the distinction between Aβ+ and Aβ- patients and the prediction of amyloid positivity, a high diagnostic accuracy for plasma p-tau181 with an AUC of 0.89 (95% CI = 0.82-0.95) was calculated. Adding the risk factors, age and APOE4, to the model did not significantly improve its performance. INTERPRETATION Our findings demonstrate that plasma p-tau181 could be a noninvasive and feasible prescreening marker for amyloid positivity in a heterogeneous clinical AD cohort and therefore help in identifying those who would benefit from more invasive assessment of amyloid pathology.
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Affiliation(s)
- Tandis Parvizi
- Department of NeurologyMedical University of ViennaViennaAustria
- Comprehensive Center for Clinical Neurosciences and Mental HealthMedical University of ViennaViennaAustria
| | - Raphael Wurm
- Department of NeurologyMedical University of ViennaViennaAustria
- Comprehensive Center for Clinical Neurosciences and Mental HealthMedical University of ViennaViennaAustria
| | - Theresa König
- Department of NeurologyMedical University of ViennaViennaAustria
- Comprehensive Center for Clinical Neurosciences and Mental HealthMedical University of ViennaViennaAustria
| | - Sara Silvaieh
- Department of NeurologyMedical University of ViennaViennaAustria
- Comprehensive Center for Clinical Neurosciences and Mental HealthMedical University of ViennaViennaAustria
| | - Patrick Altmann
- Department of NeurologyMedical University of ViennaViennaAustria
- Comprehensive Center for Clinical Neurosciences and Mental HealthMedical University of ViennaViennaAustria
| | - Sigrid Klotz
- Comprehensive Center for Clinical Neurosciences and Mental HealthMedical University of ViennaViennaAustria
- Division of Neuropathology and Neurochemistry, Department of NeurologyMedical University of ViennaViennaAustria
| | - Guenther Regelsberger
- Comprehensive Center for Clinical Neurosciences and Mental HealthMedical University of ViennaViennaAustria
- Division of Neuropathology and Neurochemistry, Department of NeurologyMedical University of ViennaViennaAustria
| | - Tatjana Traub‐Weidinger
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image‐Guided TherapyMedical University of ViennaViennaAustria
| | - Ellen Gelpi
- Comprehensive Center for Clinical Neurosciences and Mental HealthMedical University of ViennaViennaAustria
- Division of Neuropathology and Neurochemistry, Department of NeurologyMedical University of ViennaViennaAustria
| | - Elisabeth Stögmann
- Department of NeurologyMedical University of ViennaViennaAustria
- Comprehensive Center for Clinical Neurosciences and Mental HealthMedical University of ViennaViennaAustria
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Singh AK, Gambhir S, Dixit M. Automated Synthesis of [ 11C]PiB via [ 11CH 3OTf]-as Methylating Agent for PET Imaging of β-Amyloid. Curr Radiopharm 2024; 17:302-311. [PMID: 38454773 DOI: 10.2174/0118744710295705240229114137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 02/05/2024] [Accepted: 02/14/2024] [Indexed: 03/09/2024]
Abstract
AIM Efficient synthesis of precursor from commercially available starting materials and automated radiosynthesis of [11C]PiB using commercially available dedicated [11C]- Chemistry module from the synthesized precursor. BACKGROUND [11C]PiB is a promising radiotracer for PET imaging of β-Amyloid, advancing Alzheimer's disease research. The availability of precursors and protocols for efficient radiolabelling foster the applications of any radiotracer. Efficient synthesis of PiB precursor was performed using anisidine and 4-nitrobenzoyl chloride as starting materials in 5 steps, having addition, substitutions, and cyclization chemical methodologies. This precursor was used for fully automated radiosynthesis of [11C]PiB in a commercially available synthesizer, MPS-100 (SHI, Japan). The synthesized [11C]PiB was purified via solid-phase methodology, and its quality control was performed by the quality and safety criteria required for clinical use. METHODS The synthesis of desired precursors and standard authentic compounds started with commercially available materials with 70-80% yields. The standard analytical methods were characterized all synthesized compounds. The fully automated [11C]-chemistry synthesizer (MPS-100) used for radiosynthesis of [11C]PiB with [11C]CH3OTf acts as a methylating agent. For radiolabelling, varied amounts of precursor and time of reaction were explored. The resulting crude product underwent purification through solid-phase cartridges. The synthesized radiotracer was analyzed using analytical tools such as radio TLC, HPLC, pH endo-toxicity, and half-life. RESULTS The precursor for radiosynthesis of [11C]PiB was achieved in excellent yield using simple and feasible chemistry. A protocol for radiolabelling of precursor to synthesized [11C]PiB was developed using an automated synthesizer. The crude radiotracer was purified by solid-phase cartridge, with a decay-corrected radiochemical yield of 40±5% and radiochemical purity of more than 97% in approx 20 minutes (EOB). The specific activity was calculated and found in a 110-121 mCi/μmol range. CONCLUSION A reliable methodology was developed for preparing precursor followed by fully automated radiolabeling using [11C]MeOTf as a methylating agent to synthesize [11C]PiB. The final HPLC-free purification yielded more than 97% radiochemical purity tracer within one radionuclide half-life. The method was reproducible and efficient for any clinical center.
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Affiliation(s)
- Akhilesh K Singh
- Department of Nuclear Medicine, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India
| | - Sanjay Gambhir
- Department of Nuclear Medicine, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India
| | - Manish Dixit
- Department of Nuclear Medicine, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, India
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Myburgh PJ, Moore MD, Pathirannahel BL, Grace LR, Solingapuram Sai KK. Fully automated production of [ 11C]PiB for clinical use on Trasis-AllinOne synthesizer module. Appl Radiat Isot 2023; 202:111040. [PMID: 37788544 PMCID: PMC10727203 DOI: 10.1016/j.apradiso.2023.111040] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Revised: 09/21/2023] [Accepted: 09/22/2023] [Indexed: 10/05/2023]
Abstract
Pittsburgh compound B ([11C]PiB) was the first broadly applied radiotracer with specificity for amyloid-β (Aβ) peptide aggregates in the brain and has since been established as the gold standard for positron emission tomography (PET) employed for clinical in vivo imaging of Aβ plaques, used for imaging applications of Alzheimer's disease (AD), related dementia, and other tauopathies. The use of [11C]PiB for routine PET studies is dependent on the production capabilities of each radiochemistry laboratory, subsequently a continuous effort is made to develop suitable and sustainable methods on a variety of auto synthesis platforms. Here we report a fully automated, multi-step radio synthesis, purification, and reformulation of [11C]PiB for PET imaging using the Trasis AllinOne synthesis unit, a commonly used commercial radiochemistry module. We performed three validation runs to evaluate the reproducibility and to verify that the acceptable criteria were met for the release of clinical-grade [11C]PiB using a Trasis AllinOne auto radiosynthesis unit. Solid phase supported radiolabeling was performed through the capture of precursor (6-OH-BTA-0) on a C18 solid phase extraction (SPE) cartridge and subsequent flushing of gaseous [11C]Methyl triflate(MeOTf) through the Sep-Pak for carbon-11 (11C) N-methylation. Starting with 92.5 GBq [11C]CO2, [11C]PiB synthesis was completed in approximately 25 min after cyclotron end of bombardment with an injectable dose >7.0 GBq at end of the synthesis. The radiopharmaceutical product met all quality control criteria and specifications for use in human studies.
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Affiliation(s)
- Paul Josef Myburgh
- Translational Imaging Program, Atrium Health Wake Forest Baptist Medical Center, Winston-Salem, NC, 27157, USA
| | - Michael David Moore
- Translational Imaging Program, Atrium Health Wake Forest Baptist Medical Center, Winston-Salem, NC, 27157, USA
| | | | - Laura Rose Grace
- Translational Imaging Program, Atrium Health Wake Forest Baptist Medical Center, Winston-Salem, NC, 27157, USA
| | - Kiran Kumar Solingapuram Sai
- Translational Imaging Program, Atrium Health Wake Forest Baptist Medical Center, Winston-Salem, NC, 27157, USA; Department of Radiology, Atrium Health Wake Forest Baptist Medical Center, Winston-Salem, NC, 27157, USA.
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Myburgh PJ, Sai KKS. Development and Optimization of 11C-Labeled Radiotracers: A Review of the Modern Quality Control Design Process. ACS Pharmacol Transl Sci 2023; 6:1616-1631. [PMID: 37974626 PMCID: PMC10644505 DOI: 10.1021/acsptsci.3c00200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Indexed: 11/19/2023]
Abstract
Introduction - Several 11C-tracers have demonstrated high potential in early diagnostic PET imaging applications of neurodegenerative diseases including Alzheimer's and Parkinson's disease. These radiotracers often track critical biomarkers in disease pathogenesis such as tau fibrils ([11C]PBB3) or β-amyloid plaques ([11C]PiB) associated with such diseases. Purpose - The short review aims to serve as a guideline in the future development of radiotracers for students, postdocs and/or new radiochemists who will be synthesizing clinical grade or novel research 11C-tracers, including knowledge of regulatory requirements. We aim to bridge the gap between novel and established 11C-tracer quality control (QC) processes through exploring the design process and regulatory requirements for 11C-pharmaceuticals. Methods - A literature survey was undertaken to identify articles with a detailed description of the QC methodology and characterization for each of the sections of the review. Overview - First a general summary of 11C-tracer production was presented; this was used to establish possible places for contamination or assurances for a sterile final product. The key mandated QC analyses for clinical use were then discussed. Further, we assessed the QC methods used for established 11C-tracers and then reviewed the routine QC tests for preclinical translational and validation studies. Therefore, both mandated QC methods for clinical and preclinical animal studies were reviewed. Last, some examples of optimization and automation were reviewed, and implications of the QC practices associated with such procedures were considered. Conclusion - All of the common QC parameters associated with 11C-tracers under clinical and preclinical settings (along with a few exceptions) were discussed in detail. While it is important to establish standard, peer-reviewed QC testing protocols for a novel 11C-tracer entering the clinical umbrella, equal importance is needed on preclinical applications to address credibility and repeatability for the study.
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Affiliation(s)
- Paul Josef Myburgh
- Translational
Imaging Program, Atrium Health Wake Forest
Baptist Medical Center, Winston-Salem, North Carolina 27157, United States
| | - Kiran Kumar Solingapuram Sai
- Translational
Imaging Program, Atrium Health Wake Forest
Baptist Medical Center, Winston-Salem, North Carolina 27157, United States
- Department
of Radiology, Atrium Health Wake Forest
Baptist Medical Center, Winston-Salem, North Carolina 27157, United States
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Rong J, Haider A, Jeppesen TE, Josephson L, Liang SH. Radiochemistry for positron emission tomography. Nat Commun 2023; 14:3257. [PMID: 37277339 PMCID: PMC10241151 DOI: 10.1038/s41467-023-36377-4] [Citation(s) in RCA: 29] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 01/30/2023] [Indexed: 06/07/2023] Open
Abstract
Positron emission tomography (PET) constitutes a functional imaging technique that is harnessed to probe biological processes in vivo. PET imaging has been used to diagnose and monitor the progression of diseases, as well as to facilitate drug development efforts at both preclinical and clinical stages. The wide applications and rapid development of PET have ultimately led to an increasing demand for new methods in radiochemistry, with the aim to expand the scope of synthons amenable for radiolabeling. In this work, we provide an overview of commonly used chemical transformations for the syntheses of PET tracers in all aspects of radiochemistry, thereby highlighting recent breakthrough discoveries and contemporary challenges in the field. We discuss the use of biologicals for PET imaging and highlight general examples of successful probe discoveries for molecular imaging with PET - with a particular focus on translational and scalable radiochemistry concepts that have been entered to clinical use.
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Affiliation(s)
- Jian Rong
- Department of Radiology and Imaging Sciences, Emory University, 1364 Clifton Rd, Atlanta, GA, 30322, USA
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, USA
| | - Ahmed Haider
- Department of Radiology and Imaging Sciences, Emory University, 1364 Clifton Rd, Atlanta, GA, 30322, USA
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, USA
| | - Troels E Jeppesen
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, USA
| | - Lee Josephson
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, USA
| | - Steven H Liang
- Department of Radiology and Imaging Sciences, Emory University, 1364 Clifton Rd, Atlanta, GA, 30322, USA.
- Division of Nuclear Medicine and Molecular Imaging, Massachusetts General Hospital & Department of Radiology, Harvard Medical School, Boston, MA, 02114, USA.
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Jewett EM, Någren K, Mock BH, Watkins GL. 30 years of [ 11C]methyl triflate. Appl Radiat Isot 2023; 197:110812. [PMID: 37087867 DOI: 10.1016/j.apradiso.2023.110812] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 03/21/2023] [Accepted: 04/09/2023] [Indexed: 04/25/2023]
Abstract
Some scientific discoveries are well known only to a core group of researchers working on technical subjects. Nevertheless, they open new research directions, allow existing knowledge to be viewed in entirely new and useful ways, or provide a way to make something that was hard or impossible to make before. Carbon-11 methyl triflate ([11C]MeOTf) is one such advance, facilitating the synthesis of many carbon-11 radio tracers and broadening the range of applications of carbon-11 radiochemistry. The year 2022 marked the 30th anniversary of the original paper in Applied Radiation and Isotopes introducing a simple synthesis of [11C]MeOTf from carbon-11 methyl iodide ([11C]MeI) and it also marked the end of the fruitful career and life of the researcher who developed it, Douglas Jewett. It seems fitting to say a few words on how it came to be and how it has helped advance carbon-11 radiochemistry.
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Affiliation(s)
| | - Kjell Någren
- Östre Stationsvej, 36 1TH, 5000, Odense, Denmark
| | - Bruce H Mock
- Indiana University School of Medicine, Indianapolis, IN, 46202, USA
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Parvizi T, König T, Wurm R, Silvaieh S, Altmann P, Klotz S, Rommer PS, Furtner J, Regelsberger G, Lehrner J, Traub-Weidinger T, Gelpi E, Stögmann E. Real-world applicability of glial fibrillary acidic protein and neurofilament light chain in Alzheimer's disease. Front Aging Neurosci 2022; 14:887498. [PMID: 36072480 PMCID: PMC9441692 DOI: 10.3389/fnagi.2022.887498] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 07/04/2022] [Indexed: 11/13/2022] Open
Abstract
Background: Blood-based biomarkers may add a great benefit in detecting the earliest neuropathological changes in patients with Alzheimer's disease (AD). We examined the utility of neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) regarding clinical diagnosis and differentiation between amyloid positive and negative patients. To evaluate the practical application of these biomarkers in a routine clinical setting, we conducted this study in a heterogeneous memory-clinic population. Methods: We included 167 patients in this retrospective cross-sectional study, 123 patients with an objective cognitive decline [mild cognitive impairment (MCI) due to AD, n = 63, and AD-dementia, n = 60] and 44 age-matched healthy controls (HC). Cerebrospinal fluid (CSF) and plasma concentrations of NfL and GFAP were measured with single molecule array (SIMOA®) technology using the Neurology 2-Plex B kit from Quanterix. To assess the discriminatory potential of different biomarkers, age- and sex-adjusted receiver operating characteristic (ROC) curves were calculated and the area under the curve (AUC) of each model was compared. Results: We constructed a panel combining plasma NfL and GFAP with known AD risk factors (Combination panel: age+sex+APOE4+GFAP+NfL). With an AUC of 91.6% (95%CI = 0.85-0.98) for HC vs. AD and 81.7% (95%CI = 0.73-0.90) for HC vs. MCI as well as an AUC of 87.5% (95%CI = 0.73-0.96) in terms of predicting amyloid positivity, this panel showed a promising discriminatory power to differentiate these populations. Conclusion: The combination of plasma GFAP and NfL with well-established risk factors discerns amyloid positive from negative patients and could potentially be applied to identify patients who would benefit from a more invasive assessment of amyloid pathology. In the future, improved prediction of amyloid positivity with a noninvasive test may decrease the number and costs of a more invasive or expensive diagnostic approach.
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Affiliation(s)
- Tandis Parvizi
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Theresa König
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Raphael Wurm
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Sara Silvaieh
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Patrick Altmann
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Sigrid Klotz
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
| | | | - Julia Furtner
- Division of Neuroradiology and Musculoskeletal Radiology, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Günther Regelsberger
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Johann Lehrner
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Tatjana Traub-Weidinger
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, University of Vienna, Vienna, Austria
| | - Ellen Gelpi
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
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Fu L, Zhou Z, Liu L, Zhang J, Xie H, Zhang X, Zhu M, Wang R. Functional Abnormality Associated With Tau Deposition in Alzheimer's Disease - A Hybrid Positron Emission Tomography/MRI Study. Front Aging Neurosci 2021; 13:758053. [PMID: 34721001 PMCID: PMC8548365 DOI: 10.3389/fnagi.2021.758053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 09/22/2021] [Indexed: 11/21/2022] Open
Abstract
Objective: To investigate the characteristics of tau deposition and its impact on functional connectivity (FC) in Alzheimer’s disease (AD). Methods: Hybrid PET/MRI scans with [18F]-THK5317 and neuropsychological assessments were undertaken in 26 participants with AD and 19 healthy controls (HC). The standardized uptake value ratio (SUVR) of [18F]-THK5317 PET imaging was compared between the AD and HC groups. Significant clusters that revealed higher tau deposition in the AD group compared to the HC group were selected as regions of interest (ROI) for FC analysis. We evaluated the difference in the FC between the two groups for each ROI pair. The clinical and radiological characteristics were compared between the AD patients with negative FC and AD patients with positive FC for exploratory analysis. Results: The bilateral inferior lateral temporal lobe, dorsal prefrontal cortex, precuneus, posterior cingulate cortex, hippocampus, and occipital lobe showed significantly higher [18F]-THK5317 accumulation in AD patients. Decreased FC in regions with higher SUVR was observed in AD patients, and the FC strength was negatively correlated with regional SUVR. Patients with a positive FC exhibited older ages, better cognitive performances, and a lower SUVR than patients with a negative FC. Conclusions: An impact of tau deposition was observed on FC at the individual level in AD patients. Our findings suggested that the combination of tau-PET and rs-fMRI might help predict AD progression.
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Affiliation(s)
- Liping Fu
- Department of Nuclear Medicine, China-Japan Friendship Hospital, Beijing, China
| | - Zhi Zhou
- Department of Neurology, China-Japan Friendship Hospital, Beijing, China
| | - Linwen Liu
- Medical Research Center, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Jinming Zhang
- Department of Nuclear Medicine, The First Medical Center, Chinese PLA General Hospital, Beijing, China
| | - Hengge Xie
- Department of Neurology, The Second Medical Center, Chinese PLA General Hospital, Beijing, China
| | - Xiaojun Zhang
- Department of Neurology, China-Japan Friendship Hospital, Beijing, China
| | - Mingwei Zhu
- Department of Neurology, The Second Medical Center, Chinese PLA General Hospital, Beijing, China
| | - Ruimin Wang
- Department of Nuclear Medicine, The First Medical Center, Chinese PLA General Hospital, Beijing, China
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Luurtsema G, Pichler V, Bongarzone S, Seimbille Y, Elsinga P, Gee A, Vercouillie J. EANM guideline for harmonisation on molar activity or specific activity of radiopharmaceuticals: impact on safety and imaging quality. EJNMMI Radiopharm Chem 2021; 6:34. [PMID: 34628570 PMCID: PMC8502193 DOI: 10.1186/s41181-021-00149-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 09/20/2021] [Indexed: 02/04/2023] Open
Abstract
This guideline on molar activity (Am) and specific activity (As) focusses on small molecules, peptides and macromolecules radiolabelled for diagnostic and therapeutic applications. In this guideline we describe the definition of Am and As, and how these measurements must be standardised and harmonised. Selected examples highlighting the importance of Am and As in imaging studies of saturable binding sites will be given, and the necessity of using appropriate materials and equipment will be discussed. Furthermore, common Am pitfalls and remedies are described. Finally, some aspects of Am in relation the emergence of a new generation of highly sensitive PET scanners will be discussed.
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Affiliation(s)
- Gert Luurtsema
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands.
| | - Verena Pichler
- Department of Pharmaceutical Sciences, Medical University of Vienna, Vienna, Austria
| | | | - Yann Seimbille
- Department of Radiology and Nuclear Medicine, Erasmus MC, University Medical Centre Rotterdam, Rotterdam, The Netherlands
| | - Philip Elsinga
- Department of Nuclear Medicine and Molecular Imaging, University of Groningen, University Medical Centre Groningen, Groningen, The Netherlands
| | - Antony Gee
- Department of Imaging Sciences, King's College London, London, UK
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Saxena P, Mahmood T, Dixit M, Gambhir S, Ahsan F. An Exposition of 11C and 18F Radiotracers Synthesis for PET Imaging. Curr Radiopharm 2020; 14:92-100. [PMID: 33261547 DOI: 10.2174/1874471013666201201095631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2020] [Revised: 09/13/2020] [Accepted: 10/02/2020] [Indexed: 11/22/2022]
Abstract
The development of new radiolabeled Positron emission tomography tracers has been extensively utilized to access the increasing diversity in the research process and to facilitate the development in research methodology, clinical usage of drug discovery and patient care. Recent advances in radiochemistry, as well as the latest techniques in automated radio-synthesizer, have encouraged and challenged the radiochemists to produce the routinely developed radiotracers. Various radionuclides like 18F, 11C, 15O, 13N 99mTc, 131I, 124I and 64Cu are used for incorporating into different chemical scaffolds; among them, 18F and 11C tagged radiotracers are mostly explored such as 11C-Methionine, 11C-Choline, 18F-FDG, 18F-FLT, and 18F-FES. This review is focused on the development of radiochemistry routes to synthesize different radiotracers of 11C and 18F for clinical studies.
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Affiliation(s)
- Priya Saxena
- Department of Pharmacology, Faculty of Pharmacy, Integral University, Lucknow, Uttar Pradesh, India
| | - Tarique Mahmood
- Department of Pharmacology, Faculty of Pharmacy, Integral University, Lucknow, Uttar Pradesh, India
| | - Manish Dixit
- Department of Nuclear Medicine, Sanjay Gandhi Post-Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
| | - Sanjay Gambhir
- Department of Nuclear Medicine, Sanjay Gandhi Post-Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India
| | - Farogh Ahsan
- Department of Pharmacology, Faculty of Pharmacy, Integral University, Lucknow, Uttar Pradesh, India
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Chang Y, Li C, Yang H, Wu Y, Xu B, Zhang J, Wang R. 18F-Florbetaben Amyloid PET Imaging: A Chinese Study in Cognitive Normal Controls, Mild Cognitive Impairment, and Alzheimer's Disease Patients. Front Neurosci 2020; 14:745. [PMID: 32848542 PMCID: PMC7405850 DOI: 10.3389/fnins.2020.00745] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 06/24/2020] [Indexed: 11/13/2022] Open
Abstract
Objective To evaluate amyloid-β deposition with 18F-florbetaben (FBB) PET imaging against 11C-PIB PET in cognitive normal controls (NC), mild cognitive impairment (MCI), and Alzheimer’s disease (AD) patients. Methods We recruited 45 subjects (15 in each group of NC, MCI, and mild/moderate AD) who had undergone dynamic 18F-FBB amyloid PET imaging. For comparison study, 17 participants, including six NC, five MCI, and six AD patients, also underwent 11C-PIB PET imaging on separate days. Standardized uptake value ratios (SUVR) were calculated using the cerebellar cortex as the reference region with regions of interest (ROI) manually defined on co-registered CT. Quantitative analysis of mean cortical uptake was calculated using global SUVR. Spearman correlation analysis between MMSE scores and SUVR of 18F-FBB and 11C-PIB images were calculated. Results One (7%) of the 15 NC participants, nine (60%) of 15 MCI patients, and 12 (80%) of 15 AD patients had amyloid-positive lesions on 18F-FBB PET images. In AD patients, global SUVR was significantly higher than those of MCI patients (1.73 ± 0.62 vs. 1.55 ± 0.11, P < 0.001) and NC subjects (1.73 ± 0.62 vs. 1.13 ± 0.43, P < 0.001). In the comparison study, one NC participant, five MCI patients, and five AD patients had amyloid-positive lesions on 11C-PIB PET images. There was a significant linear correlation (r2 = 0.81, P < 0.001) between 18F-FBB and PIB global SUVR values. MMSE scores had negative correlations with SUVR on 11C-PIB PET (r1 = –0.650, P = 0.005) or SUVR on 18F-FBB PET (r2 = –0.754, P < 0.0001). Conclusion Our study suggests that 18F-FBB is a useful tracer for the evaluation of amyloid-β deposition in vivo and that global SUVR of 18F-FBB PET might be a reliable tool in the diagnosis of AD.
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Affiliation(s)
- Yan Chang
- Department of Nuclear Medicine, The First Medical Centre, Chinese PLA General Hospital, Beijing, China
| | - Can Li
- Department of Nuclear Medicine, The First Medical Centre, Chinese PLA General Hospital, Beijing, China
| | - Hui Yang
- Department of Nuclear Medicine, The First Medical Centre, Chinese PLA General Hospital, Beijing, China
| | - Yue Wu
- Siemens Healthineers Ltd., Beijing, China
| | - Baixuan Xu
- Department of Nuclear Medicine, The First Medical Centre, Chinese PLA General Hospital, Beijing, China
| | - Jinming Zhang
- Department of Nuclear Medicine, The First Medical Centre, Chinese PLA General Hospital, Beijing, China
| | - Ruimin Wang
- Department of Nuclear Medicine, The First Medical Centre, Chinese PLA General Hospital, Beijing, China
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Buccino P, Savio E, Porcal W. Fully-automated radiosynthesis of the amyloid tracer [ 11C] PiB via direct [ 11C]CO 2 fixation-reduction. EJNMMI Radiopharm Chem 2019; 4:14. [PMID: 31659494 PMCID: PMC6635575 DOI: 10.1186/s41181-019-0065-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Accepted: 07/05/2019] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The β-amyloid radiotracer [11C] PiB is extensively used for the Positron Emission Tomography (PET) diagnosis of Alzheimer's Disease and related dementias. For clinical use, [11C] PiB is produced using the 11C-methylation method ([11C] Methyl iodide or [11C] methyl triflate as 11C-methylation agents), which represents the most employed 11C-labelling strategy for the synthesis of 11C-radiopharmaceuticals. Recently, the use of direct [11C]CO2 fixation for the syntheses of 11C-tracers has gained interest in the radiochemical community due to its importance in terms of radiochemical versatility and for permitting the direct employment of the cyclotron-produced precursor [11C]CO2. This paper presents an optimised alternative one-pot methodology of [11C]CO2 fixation-reduction for the rapid synthesis of [11C] PiB using an automated commercial platform and its quality control. RESULTS [11C] PiB was obtained from a (25.9 ± 13.2)% (Average ± Variation Coefficient, n = 3) (end of synthesis, decay corrected) radiochemical yield from trapped [11C]CO2 after 1 min of labelling time using PhSiH3 / TBAF as the fixation-reduction system in Diglyme at 150 °C. The radiochemical purity was higher than 95% in all cases, and the molar activity was (61.4 ± 1.6) GBq/μmol. The radiochemical yield and activity (EOS) of formulated [11C] PiB from cyclotron-produced [11C]CO2 was (14.8 ± 12.1)%, decay corrected) and 9.88 GBq (± 6.0%), respectively. These are higher values compared to that of the 11C-methylation method with [11C]CH3OTf (~ 8.3%). CONCLUSIONS The viability of the system PhSiH3 / TBAF to efficiently promote the radiosynthesis of [11C] PiB via direct [11C]CO2 fixation-reduction has been demonstrated. [11C] PiB was obtained through a fully automated radiosynthesis with a satisfactory yield, purity and molar activity. According to the results, the one-pot methodology employed could reliably yield sufficiently high tracer amounts for preclinical and clinical use.
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Affiliation(s)
- Pablo Buccino
- Centro Uruguayo de Imagenología Molecular (CUDIM), Av. Dr. Américo Ricaldoni 2010, PC 11600 Montevideo, Uruguay
| | - Eduardo Savio
- Centro Uruguayo de Imagenología Molecular (CUDIM), Av. Dr. Américo Ricaldoni 2010, PC 11600 Montevideo, Uruguay
| | - Williams Porcal
- Centro Uruguayo de Imagenología Molecular (CUDIM), Av. Dr. Américo Ricaldoni 2010, PC 11600 Montevideo, Uruguay
- Departamento de Química Orgánica, Facultad de Química, Universidad de la República, Av. Gral. Flores 2124, PC 11800 Montevideo, Uruguay
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Pichler V, Zenz T, Philippe C, Vraka C, Berrotéran-Infante N, Pfaff S, Nics L, Ozenil M, Langer O, Willeit M, Traub-Weidinger T, Lanzenberger R, Mitterhauser M, Hacker M, Wadsak W. Molar activity - The keystone in 11C-radiochemistry: An explorative study using the gas phase method. Nucl Med Biol 2018; 67:21-26. [PMID: 30380463 DOI: 10.1016/j.nucmedbio.2018.09.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 09/28/2018] [Accepted: 09/29/2018] [Indexed: 12/18/2022]
Abstract
INTRODUCTION Radiochemists/radiopharmacists, involved in the preparation of radiopharmaceuticals are regularly confronted with the requirement of continuous high quality productions in their day-to-day business. One of these requirements is high specific or molar activity of the radiotracer in order to avoid e.g. receptor saturation and pharmacological or even toxic effects of the applied tracer for positron emission tomography. In the case of 11C-labeled radiotracers, the reasons for low molar activity are manifold and often the search for potential 12C-contaminations is time-consuming. METHODS In this study, diverse 12C-contaminations were analyzed and quantified, which occurred during >450 syntheses of six PET tracers using [11C]CO2 or [11C]CH3I generated via the gas phase method in a commercially available synthesizer. Additionally, non-radioactive syntheses were performed in order to identify the origins of carbon-12. RESULTS The manifold contributions to low molar activity can be attributed to three main categories, namely technical parameters (e.g. quality of target gases, reagents or tubings), inter/intralaboratory parameters (e.g. maintenance interval, burden of the module, etc.) and interoperator parameters (e.g. handling of the module). CONCLUSION Our study provides a better understanding of different factors contributing to the overall carbon load of a synthesis module, which facilitates maintenance of high molar activity of carbon-11-labeled radiopharmaceuticals.
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Affiliation(s)
- Verena Pichler
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria.
| | - Thomas Zenz
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Cécile Philippe
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Chrysoula Vraka
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Neydher Berrotéran-Infante
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Sarah Pfaff
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Lukas Nics
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Marius Ozenil
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Oliver Langer
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria; Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria; Center for Health and Bioresources, AIT Austrian Institute of Technology GmbH, Seibersdorf, Austria
| | - Matthäus Willeit
- Department of Psychiatry and Psychotherapy, Division of General Psychiatry, Medical University of Vienna, Vienna, Austria
| | - Tatjana Traub-Weidinger
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Rupert Lanzenberger
- Department of Psychiatry and Psychotherapy, Division of General Psychiatry, Medical University of Vienna, Vienna, Austria
| | - Markus Mitterhauser
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria; Ludwig-Boltzmann-Institute Applied Diagnostics, Vienna, Austria
| | - Marcus Hacker
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Wolfgang Wadsak
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria; CBmed GmbH - Center for Biomarker Research in Medicine, Graz, Austria
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14
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Pichler V, Berroterán-Infante N, Philippe C, Vraka C, Klebermass EM, Balber T, Pfaff S, Nics L, Mitterhauser M, Wadsak W. An Overview of PET Radiochemistry, Part 1: The Covalent Labels 18F, 11C, and 13N. J Nucl Med 2018; 59:1350-1354. [PMID: 30042159 DOI: 10.2967/jnumed.117.190793] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Accepted: 07/16/2018] [Indexed: 11/16/2022] Open
Abstract
This continuing educational article introduces the radiochemistry of PET tracers that exhibit a covalently bound radiolabel with the nuclides 11C, 13N, and 18F. The overall process of PET tracer production is explained, starting from the production of the radionuclide in a cyclotron; followed by the automatization process of the radiosynthesis, including the necessary steps for the respective synthesis; and finalized with the requirements for quality control.
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Affiliation(s)
- Verena Pichler
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Neydher Berroterán-Infante
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Cecile Philippe
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Chrysoula Vraka
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Eva-Maria Klebermass
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Theresa Balber
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Sarah Pfaff
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Lukas Nics
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
| | - Markus Mitterhauser
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria.,Ludwig Boltzmann Institute Applied Diagnostics, Vienna, Austria; and
| | - Wolfgang Wadsak
- Division of Nuclear Medicine, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria .,CBmed - Center for Biomarker Research in Medicine, Graz, Austria
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Brain Network Alterations in Alzheimer's Disease Identified by Early-Phase PIB-PET. CONTRAST MEDIA & MOLECULAR IMAGING 2018. [PMID: 29531506 PMCID: PMC5817202 DOI: 10.1155/2018/6830105] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The aim of this study was to identify the brain networks from early-phase 11C-PIB (perfusion PIB, pPIB) data and to compare the brain networks of patients with differentiating Alzheimer's disease (AD) with cognitively normal subjects (CN) and of mild cognitively impaired patients (MCI) with CN. Forty participants (14 CN, 12 MCI, and 14 AD) underwent 11C-PIB and 18F-FDG PET/CT scans. Parallel independent component analysis (pICA) was used to identify correlated brain networks from the 11C-pPIB and 18F-FDG data, and a two-sample t-test was used to evaluate group differences in the corrected brain networks between AD and CN, and between MCI and CN. Our study identified a brain network of perfusion (early-phase 11C-PIB) that highly correlated with a glucose metabolism (18F-FDG) brain network and colocalized with the default mode network (DMN) in an AD-specific neurodegenerative cohort. Particularly, decreased 18F-FDG uptake correlated with a decreased regional cerebral blood flow in the frontal, parietal, and temporal regions of the DMN. The group comparisons revealed similar spatial patterns of the brain networks derived from the 11C-pPIB and 18F-FDG data. Our findings indicate that 11C-pPIB derived from the early-phase 11C-PIB could provide complementary information for 18F-FDG examination in AD.
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16
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Vraka C, Mijailovic S, Fröhlich V, Zeilinger M, Klebermass EM, Wadsak W, Wagner KH, Hacker M, Mitterhauser M. Expanding LogP: Present possibilities. Nucl Med Biol 2017; 58:20-32. [PMID: 29309919 DOI: 10.1016/j.nucmedbio.2017.11.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 11/16/2017] [Accepted: 11/22/2017] [Indexed: 01/01/2023]
Abstract
INTRODUCTION Due to the high candidate exclusion rate during a drug development process, an early prediction of the pharmacokinetic behavior would be needed. Accordingly, high performance bioaffinity chromatography (HPBAC) approaches are growing in popularity, however, there is a lack of knowledge and no consensus about the relation between HPBAC measurements, in vivo distribution and blood brain barrier (BBB) penetration behavior. With respect to radiotracers, there is almost no reference data available for plasma protein binding (PPB), permeability (Pm) and the membrane coefficient (KIAM). Thus, this study was aimed at exploring the relevance of measuring PPB, Pm and KIAM for the prediction of BBB penetration. METHODS Measurements of %PPB, Pm and KIAM were performed using HPBAC. In total, 113 compounds were tested, 43 with brain uptake, 30 not showing brain uptake and 40 with known interactions with efflux transporters. Additionally, ClogP and HPLC logPowpH7.4 data were collected. RESULTS %PPB, KIAM, Pm and ClogP values were in the same range for each of the three groups. A significant difference was observed for the HPLC logPowpH7.4 between CNS penetrating drug group (CNSpos) and the non-penetrating drug group (CNSneg), as well as for the CNSneg towards the drug group interacting with efflux transporters (DRUGefflux). However, as the other experimental data, also the HPLC logPowpH7.4 showed a broad overlapping of the single values between the groupings. CONCLUSION Experimental reference values (logP, Pm, KIAM & PPB) of commonly used PET tracers and drugs showing different BBB penetration behavior are provided. The influence of the logP on brain uptake depends strongly on the selected method. However, using a single parameter (experimental or calculated) to predict BBB penetration or for the classification of drug groups is inexpedient.
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Affiliation(s)
- Chrysoula Vraka
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria; Department for Nutritional Science, University of Vienna, Vienna, Austria
| | - Sanja Mijailovic
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria; Ludwig Boltzmann Institute Applied Diagnostics, Vienna, Austria
| | - Vanessa Fröhlich
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Markus Zeilinger
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria; Faculty of Engineering, University of Applied Sciences Wiener Neustadt, Wiener Neustadt, Austria
| | - Eva-Maria Klebermass
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Wolfgang Wadsak
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria; Department of Inorganic Chemistry, University of Vienna, Vienna, Austria; CBmed, Graz, Austria
| | - Karl-Heinz Wagner
- Department for Nutritional Science, University of Vienna, Vienna, Austria
| | - Marcus Hacker
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria
| | - Markus Mitterhauser
- Department of Biomedical Imaging and Image-guided Therapy, Division of Nuclear Medicine, Medical University of Vienna, Vienna, Austria; Ludwig Boltzmann Institute Applied Diagnostics, Vienna, Austria.
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17
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Speed matters to raise molar radioactivity: Fast HPLC shortens the quality control of C-11 PET-tracers. Nucl Med Biol 2017; 57:28-33. [PMID: 29227813 DOI: 10.1016/j.nucmedbio.2017.11.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Revised: 09/25/2017] [Accepted: 11/15/2017] [Indexed: 11/23/2022]
Abstract
INTRODUCTION The decision whether an in-house produced short-lived radiopharmaceutical can be applied in-vivo is based on (1) the fulfilment of all quality criteria; (2) the availability of enough radioactivity for subsequent imaging; and (3) a molar activity (MA) above the set limits to guarantee safe administration without competing occupancy of the non-radioactive compound; and (4) an activity concentration, which is high enough for the application in certain preclinical studies. Hence, time reduction can be of major importance to increase final product yields, MA and activity concentrations. Usually, optimization in this respect only focuses on the radiotracer preparation steps but especially quality control (QC) is rarely even mentioned. Therefore, aim of this work is the establishment of optimized conditions for chromatographic analysis using HPLC within the QC to enable a significant time reduction, which then directly leads to an increase in available amount of radioactive product as well as MA at the time of application. METHODS An optimized set-up using ultra-performance liquid chromatography ((U)HPLC) was established and tested on 7 carbon-11 labelled radiotracers used within patient routine or clinical trials. RESULTS A drastic time reduction was achieved for all tracers. The optimized protocol lead to a gain of 5-7min (70-86% compared to the original set-up). CONCLUSIONS An accelerated (U)HPLC method for radiotracers labelled with short-lived radionuclides was successfully established and conditions were optimized for 7 clinically used radiotracers. The significant gain in QC time leads to a drastic increase in available radioactivity and specific activity at the time of tracer administration.
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18
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Synthesis and preliminary PET imaging of 11C and 18F isotopologues of the ROS1/ALK inhibitor lorlatinib. Nat Commun 2017; 8:15761. [PMID: 28594000 PMCID: PMC5472746 DOI: 10.1038/ncomms15761] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 04/27/2017] [Indexed: 01/27/2023] Open
Abstract
Lorlatinib (PF-06463922) is a next-generation small-molecule inhibitor of the orphan receptor tyrosine kinase c-ros oncogene 1 (ROS1), which has a kinase domain that is physiologically related to anaplastic lymphoma kinase (ALK), and is undergoing Phase I/II clinical trial investigations for non-small cell lung cancers. An early goal is to measure the concentrations of this drug in brain tumour lesions of lung cancer patients, as penetration of the blood–brain barrier is important for optimal therapeutic outcomes. Here we prepare both 11C- and 18F-isotopologues of lorlatinib to determine the biodistribution and whole-body dosimetry assessments by positron emission tomography (PET). Non-traditional radiolabelling strategies are employed to enable an automated multistep 11C-labelling process and an iodonium ylide-based radiofluorination. Carbon-11-labelled lorlatinib is routinely prepared with good radiochemical yields and shows reasonable tumour uptake in rodents. PET imaging in non-human primates confirms that this radiotracer has high brain permeability. Lorlatinib—a ROS1/ALK inhibitor—is currently undergoing clinical trials for the treatment of non-small cell lung cancers. Here the authors develop synthetic routes to 11C- and 18F-labelled lorlatinib, with subsequent PET imaging showing good blood brain barrier permeability in non-human primates.
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Stimson DHR, Pringle AJ, Maillet D, King AR, Nevin ST, Venkatachalam TK, Reutens DC, Bhalla R. Management of radioactive waste gases from PET radiopharmaceutical synthesis using cost effective capture systems integrated with a cyclotron safety system. JOURNAL OF RADIOLOGICAL PROTECTION : OFFICIAL JOURNAL OF THE SOCIETY FOR RADIOLOGICAL PROTECTION 2016; 36:504-517. [PMID: 27383139 DOI: 10.1088/0952-4746/36/3/504] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The emphasis on the reduction of gaseous radioactive effluent associated with PET radiochemistry laboratories has increased. Various radioactive gas capture strategies have been employed historically including expensive automated compression systems. We have implemented a new cost-effective strategy employing gas capture bags with electronic feedback that are integrated with the cyclotron safety system. Our strategy is suitable for multiple automated 18F radiosynthesis modules and individual automated 11C radiosynthesis modules. We describe novel gas capture systems that minimize the risk of human error and are routinely used in our facility.
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Affiliation(s)
- D H R Stimson
- Centre for Advanced Imaging, Building 57, University of Queensland, St. Lucia 4072, Brisbane, Australia
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Liger F, Eijsbouts T, Cadarossanesaib F, Tourvieille C, Le Bars D, Billard T. Direct [11C]Methylation of Amines from [11C]CO2for the Synthesis of PET Radiotracers. European J Org Chem 2015. [DOI: 10.1002/ejoc.201500924] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Liu L, Fu L, Zhang X, Zhang J, Zhang X, Xu B, Tian J, Fan Y. Combination of dynamic (11)C-PIB PET and structural MRI improves diagnosis of Alzheimer's disease. Psychiatry Res 2015; 233:131-40. [PMID: 26095348 DOI: 10.1016/j.pscychresns.2015.05.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2014] [Revised: 02/12/2015] [Accepted: 05/23/2015] [Indexed: 12/11/2022]
Abstract
Structural magnetic resonance imaging (sMRI) is an established technique for measuring brain atrophy, and dynamic positron emission tomography with (11)C-Pittsburgh compound B ((11)C-PIB PET) has the potential to provide both perfusion and amyloid deposition information. It remains unclear, however, how to better combine perfusion, amyloid deposition and morphological information extracted from dynamic (11)C-PIB PET and sMRI with the goal of improving the diagnosis of Alzheimer's disease (AD) and mild cognitive impairment (MCI). We adopted a linear sparse support vector machine to build classifiers for distinguishing AD and MCI subjects from cognitively normal (CN) subjects based on different combinations of regional measures extracted from imaging data, including perfusion and amyloid deposition information extracted from early and late frames of (11)C-PIB separately, and gray matter volumetric information extracted from sMRI data. The experimental results demonstrated that the classifier built upon the combination of imaging measures extracted from early and late frames of (11)C-PIB as well as sMRI achieved the highest classification accuracy in both classification studies of AD (100%) and MCI (85%), indicating that multimodality information could aid in the diagnosis of AD and MCI.
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Affiliation(s)
- Linwen Liu
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China; National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China
| | - Liping Fu
- Department of Nuclear Medicine, the Chinese People's Liberation Army General Hospital, Beijing 100853, China
| | - Xi Zhang
- Department of Geriatric Neurology, the Chinese People's Liberation Army General Hospital, Beijing 100853, China
| | - Jinming Zhang
- Department of Nuclear Medicine, the Chinese People's Liberation Army General Hospital, Beijing 100853, China
| | - Xiaojun Zhang
- Department of Nuclear Medicine, the Chinese People's Liberation Army General Hospital, Beijing 100853, China
| | - Baixuan Xu
- Department of Nuclear Medicine, the Chinese People's Liberation Army General Hospital, Beijing 100853, China
| | - Jiahe Tian
- Department of Nuclear Medicine, the Chinese People's Liberation Army General Hospital, Beijing 100853, China
| | - Yong Fan
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China; National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China.
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Coliva A, Monterisi C, Apollaro A, Gatti D, Penso M, Gianolli L, Perani D, Gilardi MC, Carpinelli A. Synthesis optimization of 2-(4-N-[11C]methylaminophenyl)-6-hydroxybenzothiazole ([11C]PIB), β-amyloid PET imaging tracer for Alzheimer's disease diagnosis. Appl Radiat Isot 2015; 105:66-71. [PMID: 26248085 DOI: 10.1016/j.apradiso.2015.07.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Revised: 07/01/2015] [Accepted: 07/02/2015] [Indexed: 10/23/2022]
Abstract
[11C]PIB is the most used amyloid plaques-specific positron-emitting radiotracers. The radiosynthesis of this compound, carried out by methylation of its precursor with [11C]methyl triflate in 2-butanone, has been improved optimizing the initial concentration and the purification method. Two HPLC methods were compared: good radiochemical yields, specific activities, and chemical purity above 98% were achieved by using as eluant acetonitrile/citrate and formulation in 10% ethanol.
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Affiliation(s)
- A Coliva
- Vita-Salute S. Raffaele University, Milan, Italy
| | - C Monterisi
- CNR-IBFM c/o Department of Nuclear Medicine, Ospedale San Raffaele, Via Olgettina 60, 20132 Milan, Italy
| | - A Apollaro
- CNR-IBFM c/o Department of Nuclear Medicine, Ospedale San Raffaele, Via Olgettina 60, 20132 Milan, Italy
| | - D Gatti
- Nuclear Medicine Department, IRCCS Ospedale San Raffaele, Milan, Italy
| | | | - L Gianolli
- Nuclear Medicine Department, IRCCS Ospedale San Raffaele, Milan, Italy
| | - D Perani
- Vita-Salute S. Raffaele University, Milan, Italy; CNR-IBFM c/o Department of Nuclear Medicine, Ospedale San Raffaele, Via Olgettina 60, 20132 Milan, Italy
| | - M C Gilardi
- CNR-IBFM c/o Department of Nuclear Medicine, Ospedale San Raffaele, Via Olgettina 60, 20132 Milan, Italy; Nuclear Medicine Department, IRCCS Ospedale San Raffaele, Milan, Italy
| | - A Carpinelli
- CNR-IBFM c/o Department of Nuclear Medicine, Ospedale San Raffaele, Via Olgettina 60, 20132 Milan, Italy; Nuclear Medicine Department, IRCCS Ospedale San Raffaele, Milan, Italy.
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23
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Fu L, Liu L, Zhang J, Xu B, Fan Y, Tian J. Comparison of dual-biomarker PIB-PET and dual-tracer PET in AD diagnosis. Eur Radiol 2014; 24:2800-9. [PMID: 25097125 DOI: 10.1007/s00330-014-3311-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2014] [Revised: 06/10/2014] [Accepted: 07/03/2014] [Indexed: 10/24/2022]
Abstract
OBJECTIVES To identify the optimal time window for capturing perfusion information from early (11)C-PIB imaging frames (perfusion PIB, (11)C-pPIB) and to compare the performance of (18)F-FDG PET and "dual biomarker" (11)C-PIB PET [(11)C-pPIB and amyloid PIB ((11)C-aPIB)] for classification of AD, MCI and CN subjects. METHODS Forty subjects (14 CN, 12 MCI and 14 AD patients) underwent (18)F-FDG and (11)C-PIB PET studies. Pearson correlation between the (18)F-FDG image and sum of early (11)C-PIB frames was maximised to identify the optimal time window for (11)C-pPIB. The classification power of imaging parameters was evaluated with a leave-one-out validation. RESULTS A 7-min time window yielded the highest correlation between (18)F-FDG and (11)C-pPIB. (11)C-pPIB and (18)F-FDG images shared a similar radioactive distribution pattern. (18)F-FDG performed better than (11)C-pPIB for the classification of both AD vs. CN and MCI vs. CN. (11)C-pPIB + (11)C-aPIB and (18)F-FDG + (11)C-aPIB yielded the highest classification accuracy for the classification of AD vs. CN, and (18)F-FDG + (11)C-aPIB had the best classification performance for the classification of MCI vs. CN CONCLUSION C-pPIB could serve as a useful biomarker of rCBF for measuring neural activity and improve the diagnostic power of PET for AD in conjunction with (11)C-aPIB. (18)F-FDG and (11)C-PIB dual-tracer PET examination could better detect MCI. KEY POINTS • Dual-tracer PET examination provides neurofunctional and neuropathological information for AD diagnosis. • The identified optimal 11C-pPIB time frames had highest correlation with 18F-FDG. • 11C-pPIB images shared a similar radioactive distribution pattern with 18F-FDG images. • 11C-pPIB can provide neurofunctional information. • Dual-tracer PET examination could better detect MCI.
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Affiliation(s)
- Liping Fu
- Department of Nuclear Medicine, General Hospital of the Chinese People's Liberation Army, Fuxing Rd., 28, Beijing, China
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24
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Ungersboeck J, Philippe C, Haeusler D, Mitterhauser M, Lanzenberger R, Dudczak R, Wadsak W. Optimization of [11C]DASB-synthesis: vessel-based and flow-through microreactor methods. Appl Radiat Isot 2012; 70:2615-20. [PMID: 22940416 DOI: 10.1016/j.apradiso.2012.08.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Revised: 07/24/2012] [Accepted: 08/02/2012] [Indexed: 11/25/2022]
Abstract
The intention for the present study was to implement a microfluidic set-up for N-(11)C-methylations in a flow-through microreactor device with [(11)C]DASB as model-compound and [(11)C]CH(3)I and [(11)C]CH(3)OTf, respectively, as (11)C-methylation agents. Due to an observed "aging" effect of the (11)C-methylation agents' solution, this goal was not achieved. Nevertheless, based on these observations, the time consumption for the vessel-based routine production of [(11)C]DASB was reduced (34±1 min) and RCY was increased to 45.1±4.6% (EOB; 5.2±0.95 GBq EOS).
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Affiliation(s)
- Johanna Ungersboeck
- Radiochemistry and Biomarker Development Unit, Department of Nuclear Medicine, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria
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25
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Cai L, Xu R, Guo X, Pike VW. Rapid Room-Temperature 11C-Methylation of Arylamines with [ 11C]Methyl Iodide Promoted by Solid Inorganic Bases in DMF. European J Org Chem 2012; 2012:1303-1310. [PMID: 24659907 DOI: 10.1002/ejoc.201101499] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
11[C]Methyl iodide is the most widely used reagent for labeling radiotracers with carbon-11 (t1/2 = 20.4 min) for molecular imaging with positron emission tomography. However, some substrates for labeling, especially primary arylamines and pyrroles, are sluggishly reactive towards [11C]methyl iodide. We found that insoluble inorganic bases, especially Li3N or Li2O, are effective in promoting rapid reactions (≤ 10 min) of such substrates with no-carrier-added [11C]methyl iodide in DMF at room temperature to give 11C-methylated products in useful radiochemical yields. In particular, we discovered that some primary arylamines in Li3N-DMF were converted into their formanilides, and that these were readily N-methylated with [11C]methyl iodide, preceding easy basic hydrolysis to the desired [11C]N-methyl secondary arylamines. Use of a solid base permitted selective reaction at an arylamino group and in some cases also avoided undesirable side reaction, such as ester group hydrolysis. An ultrasound device proved useful to provide remote and constant agitation of the radioactive heterogeneous reaction mixtures, but imparted no 'ultrasound-specific' chemical effect.
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Affiliation(s)
- Lisheng Cai
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Drive, Building 10, Room B3 C346A, Bethesda MD 20892, USA
| | - Rong Xu
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Drive, Building 10, Room B3 C346A, Bethesda MD 20892, USA
| | - Xuelei Guo
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Drive, Building 10, Room B3 C346A, Bethesda MD 20892, USA
| | - Victor W Pike
- Molecular Imaging Branch, National Institute of Mental Health, National Institutes of Health, 10 Center Drive, Building 10, Room B3 C346A, Bethesda MD 20892, USA
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