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Vyakaranam AR, Mahamed MM, Hellman P, Eriksson O, Espes D, Christoffersson G, Sundin A. Non-invasive imaging of sympathetic innervation of the pancreas in individuals with type 2 diabetes. Diabetologia 2024; 67:199-208. [PMID: 37935826 PMCID: PMC10709256 DOI: 10.1007/s00125-023-06039-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Accepted: 07/31/2023] [Indexed: 11/09/2023]
Abstract
AIMS/HYPOTHESIS Compromised pancreatic sympathetic innervation has been suggested as a factor involved in both immune-mediated beta cell destruction and endocrine dysregulation of pancreatic islets. To further explore these intriguing findings, new techniques for in vivo assessment of pancreatic innervation are required. This is a retrospective study that aimed to investigate whether the noradrenaline (norepinephrine) analogue 11C-hydroxy ephedrine (11C-HED) could be used for quantitative positron emission tomography (PET) imaging of the sympathetic innervation of the human pancreas. METHODS In 25 individuals with type 2 diabetes and 64 individuals without diabetes, all of whom had previously undergone 11C-HED-PET/CT because of pheochromocytoma or paraganglioma (or suspicion thereof), the 11C-HED standardised uptake value (SUVmean), 11C-HED specific binding index (SBI), pancreatic functional volume (FV, in ml), functional neuronal volume (FNV, calculated as SUVmean × FV), specific binding index with functional volume (SBI FV, calculated as SBI × FV) and attenuation on CT (HU) were investigated in the entire pancreas, and additionally in six separate anatomical pancreatic regions. RESULTS Generally, 11C-HED uptake in the pancreas was high, with marked individual variation, suggesting variability in sympathetic innervation. Moreover, pancreatic CT attenuation (HU) (p<0.001), 11C-HED SBI (p=0.0049) and SBI FV (p=0.0142) were lower in individuals with type 2 diabetes than in individuals without diabetes, whereas 11C-HED SUVmean (p=0.15), FV (p=0.73) and FNV (p=0.30) were similar. CONCLUSIONS/INTERPRETATION We demonstrate the feasibility of using 11C-HED-PET for non-invasive assessment of pancreatic sympathetic innervation in humans. These findings warrant further prospective evaluation, especially in individuals with theoretical defects in pancreatic sympathetic innervation, such as those with type 1 diabetes.
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Affiliation(s)
- Achyut Ram Vyakaranam
- Department of Surgical Sciences, Section of Radiology & Molecular Imaging, Uppsala University, Uppsala, Sweden.
| | - Maryama M Mahamed
- Department of Surgical Sciences, Section of Radiology & Molecular Imaging, Uppsala University, Uppsala, Sweden
| | - Per Hellman
- Department of Surgical Sciences, Section of Radiology & Molecular Imaging, Uppsala University, Uppsala, Sweden
| | - Olof Eriksson
- Science for Life Laboratory, Department of Medicinal Chemistry, Uppsala University, Uppsala, Sweden
| | - Daniel Espes
- Science for Life Laboratory, Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
- Science for Life Laboratory, Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Gustaf Christoffersson
- Science for Life Laboratory, Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Anders Sundin
- Department of Surgical Sciences, Section of Radiology & Molecular Imaging, Uppsala University, Uppsala, Sweden
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Bini J, Carson RE, Cline GW. Noninvasive Quantitative PET Imaging in Humans of the Pancreatic Beta-Cell Mass Biomarkers VMAT2 and Dopamine D2/D3 Receptors In Vivo. Methods Mol Biol 2023; 2592:61-74. [PMID: 36507985 DOI: 10.1007/978-1-0716-2807-2_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Noninvasive quantitative imaging of beta-cells can provide information on changes in cellular transporters, receptors, and signaling proteins that may affect function and/or loss of mass, both of which contribute to the loss of insulin secretion and glucose regulation of patients with type 1 or type 2 diabetes (T1D/T2D). We have developed and optimized the use of two positron emission tomography (PET) radioligands, [18F]FP-(+)-DTBZ and [11C](+)-PHNO, targeting beta-cell VMAT2 and dopamine (D2/D3) receptors, respectively. Here we describe our optimized methodology for the clinical use of these two tracers for quantitative PET imaging of beta-cell biomarkers in vivo. We also briefly discuss our previous results and their implications and value towards extending the use of PET radioligand beyond the original goal of quantitative imaging of beta-cell mass to the potential to provide insight into the biology of beta-cell loss of mass and/or function and to evaluate the efficacy of therapeutics to prevent or restore functional beta-cell mass.
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Affiliation(s)
- Jason Bini
- PET Center, Yale University School of Medicine, New Haven, CT, USA.
| | - Richard E Carson
- PET Center, Yale University School of Medicine, New Haven, CT, USA
| | - Gary W Cline
- Department of Internal Medicine, Division of Endocrinology, Yale University School of Medicine, New Haven, CT, USA
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3
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de Vries EFJ, Elsinga PH, Tsoumpas C. Will extended field-of-view PET/CT depopulate the graveyard of failed PET radiopharmaceuticals? Cancer Imaging 2022; 22:70. [PMID: 36529738 PMCID: PMC9761966 DOI: 10.1186/s40644-022-00510-1] [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: 12/07/2022] [Accepted: 12/08/2022] [Indexed: 12/23/2022] Open
Abstract
With the rapid emergence of extended Field-of-View PET-cameras several new applications for radiopharmaceuticals become within reach. Main reason is the significant increase of the sensitivity of the PET-camera so that much less radioactivity can be administered. Issues that that hampered development or use of PET-radiopharmaceuticals become realistic again. Molar activity requirements can become less strict. New low-yielding radiochemistry methods may become applicable. Carbon-11 labelled compounds can revive and potentially be shipped to nearby PET-facilities. PET-radiopharmaceuticals with slow kinetics in comparison to their half life can still be used. As additional infrastructure and equipment will likely remain unchanged and keep the same sensitivity therefore there will be issues with kinetic modelling requiring analysis of plasma or metabolites samples with lower count rate. Besides the potential revival of failed radiopharmaceuticals, novel challenges are ahead to develop novel radiochemistry based on thus far unsuitable (low yielding or time consuming) reactions.
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Affiliation(s)
- E. F. J. de Vries
- grid.4494.d0000 0000 9558 4598Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, Hanzeplein 1, Groningen, 9713GZ The Netherlands
| | - P. H. Elsinga
- grid.4494.d0000 0000 9558 4598Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, Hanzeplein 1, Groningen, 9713GZ The Netherlands
| | - C. Tsoumpas
- grid.4494.d0000 0000 9558 4598Department of Nuclear Medicine and Molecular Imaging, University Medical Center Groningen, Hanzeplein 1, Groningen, 9713GZ The Netherlands
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Bini J, Lattin CR, Toyonaga T, Finnema SJ, Carson R. Optimized Methodology for Reference Region and Image-Derived Input Function Kinetic Modeling in Preclinical PET. IEEE TRANSACTIONS ON RADIATION AND PLASMA MEDICAL SCIENCES 2022; 6:454-462. [PMID: 36185820 PMCID: PMC9524424 DOI: 10.1109/trpms.2021.3088606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
PET imaging of small animals is often used for assessing biodistribution of a novel radioligand and pharmacology in small animal models of disease. PET acquisition and processing settings may affect reference region or image-derived input function (IDIF) kinetic modeling estimates. We examined four different factors in comparing quantitative results: 1) effect of reconstruction algorithm, 2) number of MAP iterations, 3) strength of the MAP prior, and 4) Attenuation and scatter. The effect of these parameters has not been explored for small-animal reference region and IDIF kinetic modeling approaches. Dynamic PET/CT scans were performed in 3 species with 3 different tracers: house sparrows with [11C]raclopride, rats with [18F]AS2471907 (11βHSD1) and mice with [11C]UCB-J (SV2A). FBP yielded lower kinetic modeling estimates compared to 3D-OSEM-MAP reconstructions, in sparrow and rat studies. Target resolutions (MAP prior strength) of 1.5 and 3.0mm demonstrated reduced VT in rats but only 3.0mm reduced BP ND in sparrows. Therefore, use of the highest target resolution (0.8mm) is warranted. We demonstrated using kinetic modeling that forgoing CT-based attenuation and scatter correction may be appropriate to improve animal throughput when using short-lived radioisotopes in sparrows and mice. This work provides recommendations and a framework for future optimization of kinetic modeling for preclinical PET methodology with novel radioligands.
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Affiliation(s)
- Jason Bini
- Yale School of Medicine, New Haven, CT, USA
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5
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Zeynaloo E, Stone LD, Dikici E, Ricordi C, Deo SK, Bachas LG, Daunert S, Lanzoni G. Delivery of therapeutic agents and cells to pancreatic islets: Towards a new era in the treatment of diabetes. Mol Aspects Med 2021; 83:101063. [PMID: 34961627 DOI: 10.1016/j.mam.2021.101063] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Revised: 12/09/2021] [Accepted: 12/13/2021] [Indexed: 02/07/2023]
Abstract
Pancreatic islet cells, and in particular insulin-producing beta cells, are centrally involved in the pathogenesis of diabetes mellitus. These cells are of paramount importance for the endocrine control of glycemia and glucose metabolism. In Type 1 Diabetes, islet beta cells are lost due to an autoimmune attack. In Type 2 Diabetes, beta cells become dysfunctional and insufficient to counterbalance insulin resistance in peripheral tissues. Therapeutic agents have been developed to support the function of islet cells, as well as to inhibit deleterious immune responses and inflammation. Most of these agents have undesired effects due to systemic administration and off-target effects. Typically, only a small fraction of therapeutic agent reaches the desired niche in the pancreas. Because islets and their beta cells are scattered throughout the pancreas, access to the niche is limited. Targeted delivery to pancreatic islets could dramatically improve the therapeutic effect, lower the dose requirements, and lower the side effects of agents administered systemically. Targeted delivery is especially relevant for those therapeutics for which the manufacturing is difficult and costly, such as cells, exosomes, and microvesicles. Along with therapeutic agents, imaging reagents intended to quantify the beta cell mass could benefit from targeted delivery. Several methods have been developed to improve the delivery of agents to pancreatic islets. Intra-arterial administration in the pancreatic artery is a promising surgical approach, but it has inherent risks. Targeted delivery strategies have been developed based on ligands for cell surface molecules specific to islet cells or inflamed vascular endothelial cells. Delivery methods range from nanocarriers and vectors to deliver pharmacological agents to viral and non-viral vectors for the delivery of genetic constructs. Several strategies demonstrated enhanced therapeutic effects in diabetes with lower amounts of therapeutic agents and lower off-target side effects. Microvesicles, exosomes, polymer-based vectors, and nanocarriers are gaining popularity for targeted delivery. Notably, liposomes, lipid-assisted nanocarriers, and cationic polymers can be bioengineered to be immune-evasive, and their advantages to transport cargos into target cells make them appealing for pancreatic islet-targeted delivery. Viral vectors have become prominent tools for targeted gene delivery. In this review, we discuss the latest strategies for targeted delivery of therapeutic agents and imaging reagents to pancreatic islet cells.
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Affiliation(s)
- Elnaz Zeynaloo
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, USA; Department of Chemistry, University of Miami, FL, USA.
| | - Logan D Stone
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL, USA; Department of Surgery, University of Miami Miller School of Medicine, Miami, FL, USA.
| | - Emre Dikici
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, USA; Dr. John T. Macdonald Foundation Biomedical Nanotechnology Institute - BioNIUM at University of Miami, Miami, FL, USA
| | - Camillo Ricordi
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL, USA; Department of Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Sapna K Deo
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, USA; Dr. John T. Macdonald Foundation Biomedical Nanotechnology Institute - BioNIUM at University of Miami, Miami, FL, USA
| | - Leonidas G Bachas
- Department of Chemistry, University of Miami, FL, USA; Dr. John T. Macdonald Foundation Biomedical Nanotechnology Institute - BioNIUM at University of Miami, Miami, FL, USA
| | - Sylvia Daunert
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, USA; Dr. John T. Macdonald Foundation Biomedical Nanotechnology Institute - BioNIUM at University of Miami, Miami, FL, USA; Clinical and Translational Science Institute, University of Miami, Miami, FL, USA
| | - Giacomo Lanzoni
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, USA; Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL, USA; Dr. John T. Macdonald Foundation Biomedical Nanotechnology Institute - BioNIUM at University of Miami, Miami, FL, USA.
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Cheung P, Eriksson O. The Current State of Beta-Cell-Mass PET Imaging for Diabetes Research and Therapies. Biomedicines 2021; 9:1824. [PMID: 34944640 PMCID: PMC8698817 DOI: 10.3390/biomedicines9121824] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 11/28/2021] [Accepted: 11/30/2021] [Indexed: 12/03/2022] Open
Abstract
Diabetes is a chronic metabolic disease affecting over 400 million people worldwide and one of the leading causes of death, especially in developing nations. The disease is characterized by chronic hyperglycemia, caused by defects in the insulin secretion or action pathway. Current diagnostic methods measure metabolic byproducts of the disease such as glucose level, glycated hemoglobin (HbA1c), insulin or C-peptide levels, which are indicators of the beta-cell function. However, they inaccurately reflect the disease progression and provide poor longitudinal information. Beta-cell mass has been suggested as an alternative approach to study disease progression in correlation to beta-cell function, as it behaves differently in the diabetes physiopathology. Study of the beta-cell mass, however, requires highly invasive and potentially harmful procedures such as pancreatic biopsies, making diagnosis and monitoring of the disease tedious. Nuclear medical imaging techniques using radiation emitting tracers have been suggested as strong non-invasive tools for beta-cell mass. A highly sensitive and high-resolution technique, such as positron emission tomography, provides an ideal solution for the visualization of beta-cell mass, which is particularly essential for better characterization of a disease such as diabetes, and for estimating treatment effects towards regeneration of the beta-cell mass. Development of novel, validated biomarkers that are aimed at beta-cell mass imaging are thus highly necessary and would contribute to invaluable breakthroughs in the field of diabetes research and therapies. This review aims to describe the various biomarkers and radioactive probes currently available for positron emission tomography imaging of beta-cell mass, as well as highlight the need for precise quantification and visualization of the beta-cell mass for designing new therapy strategies and monitoring changes in the beta-cell mass during the progression of diabetes.
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Affiliation(s)
- Pierre Cheung
- Science for Life Laboratory, Department of Medicinal Chemistry, Uppsala University, SE-75183 Uppsala, Sweden;
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7
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The utilization of positron emission tomography in the evaluation of renal health and disease. Clin Transl Imaging 2021. [DOI: 10.1007/s40336-021-00469-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Abstract
Purpose
Positron emission tomography (PET) is a nuclear imaging technique that uses radiotracers to visualize metabolic processes of interest across different organs, to diagnose and manage diseases, and monitor therapeutic response. This systematic review aimed to characterize the value of PET for the assessment of renal metabolism and function in subjects with non-oncological metabolic disorders.
Methods
This review was conducted and reported in accordance with the PRISMA statement. Research articles reporting “kidney” or “renal” metabolism evaluated with PET imaging between 1980 and 2021 were systematically searched in Medline/PubMed, Science Direct, and the Cochrane Library. Search results were exported and stored in RefWorks, the duplicates were removed, and eligible studies were identified, evaluated, and summarized.
Results
Thirty reports met the inclusion criteria. The majority of the studies were prospective (73.33%, n = 22) in nature. The most utilized PET radiotracers were 15O-labeled radio water (H215O, n = 14) and 18F-fluorodeoxyglucose (18F-FDG, n = 8). Other radiotracers used in at least one study were 14(R,S)-(18)F-fluoro-6-thia-heptadecanoic acid (18F-FTHA), 18F-Sodium Fluoride (18F-NaF), 11C-acetate, 68-Gallium (68Ga), 13N-ammonia (13N-NH3), Rubidium-82 (82Rb), radiolabeled cationic ferritin (RadioCF), 11C‐para-aminobenzoic acid (11C-PABA), Gallium-68 pentixafor (68Ga-Pentixafor), 2-deoxy-2-F-fluoro-d-sorbitol (F-FDS) and 55Co-ethylene diamine tetra acetic acid (55Co-EDTA).
Conclusion
PET imaging provides an effective modality for evaluating a range of metabolic functions including glucose and fatty acid uptake, oxygen consumption and renal perfusion. Multiple positron emitting radiolabeled racers can be used for renal imaging in clinical settings. PET imaging thus holds the potential to improve the diagnosis of renal disorders, and to monitor disease progression and treatment response.
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Dai Y, Sa R, Guan F, Wang Q, Li Y, Zhao H. A Purification Method of 18F-FP-(+)-DTBZ via Solid-Phase Extraction With Combined Cartridges. Front Med (Lausanne) 2021; 8:693632. [PMID: 34307421 PMCID: PMC8298858 DOI: 10.3389/fmed.2021.693632] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Accepted: 06/17/2021] [Indexed: 11/13/2022] Open
Abstract
Background: To optimize [18F] 9-fluoropropyl-(+)-dihydrotetrabenazine (18F-FP-(+)-DTBZ) purification via solid-phase extraction (SPE) with combined cartridges to facilitate its widespread clinical application. Methods: A modified SPE purification method, employing Sep-Pak PS-2 and Sep-Pak C18 cartridges, was used for the preparation of 18F-FP-(+)-DTBZ. This method was compared to the purification method of high-pressure liquid chromatography (HPLC) and SPE with one cartridge, following quality control test and positron emission tomography (PET) imaging in healthy volunteers and patients with parkinsn's disease (PD). Results: A SPE purification method integrating Sep-Pak PS-2 and Sep-Pak C18 cartridges was implemented successfully. The retention time of 18F-FP-(+)-DTBZ purified by HPLC, SPE with Sep-Pak PS-2, SPE with Sep-Pak C18, and SPE with combined use of Sep-Pak PS-2 and Sep-Pak C18 cartridges was 8.7, 8.8, 8.7, and 8.9 min, respectively. Fewest impurity peak was detected in 18F-FP-(+)-DTBZ purified by the SPE with combined use of Sep-Pak PS-2 and Sep-Pak C18 cartridges. This modified SPE purification method provided a satisfactory radiochemical yield of 29 ± 1.8% with radiochemical purity >99% and shortened synthesis time to 27 min. The brain uptake of 18F-FP-(+)-DTBZ purified by the modified SPE was comparable to that purified by HPLC in both healthy volunteers and PD patients. Conclusions: A SPE method integrating Sep-Pak PS-2 and Sep-Pak C18 cartridges for purification of 18F-FP-(+)-DTBZ may be highly suited to automatic synthesis for routine clinical applications, as it provides excellent radiochemical purity, high yield as well as operational simplicity.
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Affiliation(s)
- Yuyin Dai
- Department of Nuclear Medicine, The First Hospital of Jilin University, Changchun, China
| | - Ri Sa
- Department of Nuclear Medicine, The First Hospital of Jilin University, Changchun, China
| | - Feng Guan
- Department of Nuclear Medicine, The First Hospital of Jilin University, Changchun, China
| | - Qi Wang
- Department of Nuclear Medicine, The First Hospital of Jilin University, Changchun, China
| | - Yinghua Li
- Department of Nuclear Medicine, The First Hospital of Jilin University, Changchun, China
| | - Hongguang Zhao
- Department of Nuclear Medicine, The First Hospital of Jilin University, Changchun, China
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Zhao C, Liu C, Tang J, Xu Y, Xie M, Chen Z. An Efficient Automated Radiosynthesis and Bioactivity Confirmation of VMAT2 Tracer [ 18F]FP-(+)-DTBZ. Mol Imaging Biol 2021; 22:265-273. [PMID: 31165386 DOI: 10.1007/s11307-019-01379-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
PURPOSE The aim of this study was to optimize the radiolabeling method of [18F]fluoropropyl-(+)-dihydrotetrabenazine ([18F]FP-(+)-DTBZ) to fulfill the demand of preclinical and clinical application. PROCEDURES Optimized labeling conditions were performed by altering the molar ratio of precursor to base (P/B), base species, solvents, reaction temperature, reaction time, and precursor concentration through manual radiosynthesis of [18F]FP-(+)-DTBZ. The conditions with the highest radiochemical yield (RCY) were applied to automated radiosynthesis, and the crude product was purified with a Sep-Pak Plus C18 cartridge. Quality control and stability of [18F]FP-(+)-DTBZ were carried out by HPLC. In vitro cellular uptake and blocking assays were conducted in human neuroblastoma cell line SH-SY5Y. In vivo imaging with small animal positron emission tomography (microPET) was performed with Sprague-Dawley rats. RESULTS Under the optimized conditions (P/K2CO3 = 1:8, heating at 120 °C for 3 min in dimethyl sulfoxide), an RCY of 88.7 % was obtained with 1.0 mg precursor. The optimized reaction conditions were successfully applied to an automated module and gave a high activity yield (AY) of 30-55 % in about 40 min with a > 99.0 % radiochemical purity (RCP) and a > 44.4 GBq/μmol molar activity (Am). Stability test displayed that the RCP retained > 98.0 % in 8 h in saline and in phosphate buffer saline (PBS, pH 7.4). In vitro cellular uptake assay showed accumulation of [18F]FP-(+)-DTBZ in SH-SY5Y cells, which could be significantly inhibited by vesicular monoamine transporter 2 (VMAT2) inhibitor DTBZ. MicroPET images of rat brain displayed that the striatum showed the highest uptake with a standardized uptake value (SUV) of 3.91 ± 0.30 at ~ 70 min. Co-injection with DTBZ (1.0 mg/kg) resulted in a 75 % decrease of the striatal SUV, confirming the specificity of [18F]FP-(+)-DTBZ to VMAT2. CONCLUSIONS We obtained an optimized radiolabeling method of [18F]FP-(+)-DTBZ and successfully applied it to a commercial available module. The automated synthesis gave a high AY and RCP of [18F]FP-(+)-DTBZ with high and specific binding to VMAT2, facilitating its routine application for VMAT2 tracing.
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Affiliation(s)
- Chao Zhao
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, School of Pharmacy, Xuzhou Medical University, Xuzhou, 221004, China
| | - Chunyi Liu
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, 214063, China
| | - Jie Tang
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, 214063, China
| | - Yingjiao Xu
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, 214063, China
| | - Minhao Xie
- Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, 214063, China
| | - Zhengping Chen
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, School of Pharmacy, Xuzhou Medical University, Xuzhou, 221004, China. .,Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi, 214063, China.
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Demine S, Schulte ML, Territo PR, Eizirik DL. Beta Cell Imaging-From Pre-Clinical Validation to First in Man Testing. Int J Mol Sci 2020; 21:E7274. [PMID: 33019671 PMCID: PMC7582644 DOI: 10.3390/ijms21197274] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 09/21/2020] [Accepted: 09/28/2020] [Indexed: 12/14/2022] Open
Abstract
There are presently no reliable ways to quantify human pancreatic beta cell mass (BCM) in vivo, which prevents an accurate understanding of the progressive beta cell loss in diabetes or following islet transplantation. Furthermore, the lack of beta cell imaging hampers the evaluation of the impact of new drugs aiming to prevent beta cell loss or to restore BCM in diabetes. We presently discuss the potential value of BCM determination as a cornerstone for individualized therapies in diabetes, describe the presently available probes for human BCM evaluation, and discuss our approach for the discovery of novel beta cell biomarkers, based on the determination of specific splice variants present in human beta cells. This has already led to the identification of DPP6 and FXYD2ga as two promising targets for human BCM imaging, and is followed by a discussion of potential safety issues, the role for radiochemistry in the improvement of BCM imaging, and concludes with an overview of the different steps from pre-clinical validation to a first-in-man trial for novel tracers.
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Affiliation(s)
- Stephane Demine
- Indiana Biosciences Research Institute, Indianapolis, IN 46202, USA;
| | - Michael L. Schulte
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (M.L.S.); (P.R.T.)
| | - Paul R. Territo
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN 46202, USA; (M.L.S.); (P.R.T.)
- Division of Clinical Pharmacology, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Decio L. Eizirik
- Indiana Biosciences Research Institute, Indianapolis, IN 46202, USA;
- ULB Center for Diabetes Research, Medical Faculty, Université Libre de Bruxelles (ULB), 1070 Brussels, Belgium
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Current Progress and Perspective: Clinical Imaging of Islet Transplantation. Life (Basel) 2020; 10:life10090213. [PMID: 32961769 PMCID: PMC7555367 DOI: 10.3390/life10090213] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 09/17/2020] [Accepted: 09/17/2020] [Indexed: 12/13/2022] Open
Abstract
Islet transplantation has great potential as a cure for type 1 diabetes. At present; the lack of a clinically validated non-invasive imaging method to track islet grafts limits the success of this treatment. Some major clinical imaging modalities and various molecular probes, which have been studied for non-invasive monitoring of transplanted islets, could potentially fulfill the goal of understanding pathophysiology of the functional status and viability of the islet grafts. In this current review, we summarize the recent clinical studies of a variety of imaging modalities and molecular probes for non-invasive imaging of transplanted beta cell mass. This review also includes discussions on in vivo detection of endogenous beta cell mass using clinical imaging modalities and various molecular probes, which will be useful for longitudinally detecting the status of islet transplantation in Type 1 diabetic patients. For the conclusion and perspectives, we highlight the applications of multimodality and novel imaging methods in islet transplantation.
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Kong Y, Zhou H, Feng H, Zhuang J, Wen T, Zhang C, Sun B, Wang J, Guan Y. Elucidating the Relationship Between Diabetes Mellitus and Parkinson's Disease Using 18F-FP-(+)-DTBZ, a Positron-Emission Tomography Probe for Vesicular Monoamine Transporter 2. Front Neurosci 2020; 14:682. [PMID: 32760240 PMCID: PMC7372188 DOI: 10.3389/fnins.2020.00682] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2020] [Accepted: 06/03/2020] [Indexed: 01/25/2023] Open
Abstract
Diabetes mellitus (DM) and Parkinson’s disease (PD) have been and will continue to be two common chronic diseases globally that are difficult to diagnose during the prodromal phase. Current molecular genetics, cell biological, and epidemiological evidences have shown the correlation between PD and DM. PD shares the same pathogenesis pathways and pathological factors with DM. In addition, β-cell reduction, which can cause hyperglycemia, is a striking feature of DM. Recent studies indicated that hyperglycemia is highly relevant to the pathologic changes in PD. However, further correlation between DM and PD remains to be investigated. Intriguingly, polycystic monoamine transporter 2 (VMAT2), which is co-expressed in dopaminergic neurons and β cells, is responsible for taking up dopamine into the presynaptic vesicles and can specifically bind to the β cells. Furthermore, we have summarized the specific molecular and diagnostic functions of VMAT2 for the two diseases reported in this review. Therefore, VMAT2 can be applied as a target probe for positron emission tomography (PET) imaging to detect β-cell and dopamine level changes, which can contribute to the diagnosis of DM and PD during the prodromal phase. Targeting VMAT2 with the molecular probe 18F-FP-(+)-DTBZ can be an entry point for the β cell mass (BCM) changes in DM at the molecular level, to clarify the potential relationship between DM and PD. VMAT2 has promising clinical significance in investigating the pathogenesis, early diagnosis, and treatment evaluation of the two diseases.
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Affiliation(s)
- Yanyan Kong
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
| | - Haicong Zhou
- Laboratory of Molecular Neural Biology, School of Life Sciences, Shanghai University, Shanghai, China
| | - Hu Feng
- Laboratory of Molecular Neural Biology, School of Life Sciences, Shanghai University, Shanghai, China
| | - Junyi Zhuang
- Laboratory of Molecular Neural Biology, School of Life Sciences, Shanghai University, Shanghai, China
| | - Tieqiao Wen
- Laboratory of Molecular Neural Biology, School of Life Sciences, Shanghai University, Shanghai, China
| | - Chencheng Zhang
- Department of Neurosurgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Bomin Sun
- Department of Neurosurgery, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jiao Wang
- Laboratory of Molecular Neural Biology, School of Life Sciences, Shanghai University, Shanghai, China
| | - Yihui Guan
- PET Center, Huashan Hospital, Fudan University, Shanghai, China
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13
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News ways of understanding the complex biology of diabetes using PET. Nucl Med Biol 2020; 92:65-71. [PMID: 32387114 DOI: 10.1016/j.nucmedbio.2020.04.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 03/27/2020] [Accepted: 04/15/2020] [Indexed: 11/22/2022]
Abstract
The understanding of metabolic disease and diabetes on a molecular level has increased significantly due to the recent advances in molecular biology and biotechnology. However, in vitro studies and animal models do not always translate to the human disease, perhaps illustrated by the failure of many drug candidates in the clinical phase. Non-invasive biomedical imaging techniques such as Positron Emission Tomography (PET) offer tools for direct visualization and quantification of molecular processes in humans. Developments in this area potentially enable longitudinal in vivo studies of receptors and processes involved in diabetes guiding drug development and diagnosis in the near future. This mini-review focuses on describing the overall perspective of how PET can be used to increase our understanding and improve treatment of diabetes. The methodological aspects and future developments and challenges are highlighted.
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14
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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] [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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15
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Hillmer AT, Matuskey D, Huang Y, Nabulsi N, Ropchan J, Carson RE, O'Malley SS, Cosgrove KP. Tobacco Smoking in People Is Not Associated with Altered 18-kDa Translocator Protein Levels: A PET Study. J Nucl Med 2020; 61:1200-1204. [PMID: 32005773 DOI: 10.2967/jnumed.119.237735] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Accepted: 12/19/2019] [Indexed: 11/16/2022] Open
Abstract
The effects of tobacco smoking on the immune system of the brain are not well elucidated. Although nicotine is immunosuppressive, other constituents in tobacco smoke have inflammatory effects. PET imaging of the 18-kDa translocator protein (TSPO) provides a biomarker for microglia, the primary immunocompetent cells of the brain. This work compared brain TSPO levels in 20 tobacco smokers (abstinent for at least 2 h) and 20 nonsmokers using a fully quantitative modeling approach for the first time, to our knowledge. Methods: 11C-PBR28 (N-((2-(methoxy-11C)-phenyl)methyl)-N-(6-phenoxy-3-pyridinyl)acetamide) PET scans were acquired with arterial blood sampling to estimate the metabolite-corrected input function. 11C-PBR28 volumes of distribution were estimated throughout the brain with multilinear analysis. Results: Statistical analyses revealed no evidence of significant differences in regional 11C-PBR28 volumes of distribution between smokers and nonsmokers (whole-brain Cohen d = 0.09) despite adequate power to detect medium effect sizes. Conclusion: These findings inform previous PET studies reporting lower TSPO radiotracer concentrations in the brain (measured as SUV) for tobacco smokers than for nonsmokers by demonstrating the importance of accounting for radiotracer concentrations in plasma. These findings suggest that nonsmokers and smokers have comparable TSPO levels in the brain. Additional work with other biomarkers is needed to fully characterize the effects of tobacco smoking on the brain immune system.
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Affiliation(s)
- Ansel T Hillmer
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut .,Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut.,Yale University PET Center, Yale University School of Medicine, New Haven, Connecticut.,Department of Biomedical Engineering, Yale School of Engineering and Applied Science, New Haven, Connecticut
| | - David Matuskey
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut.,Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut.,Yale University PET Center, Yale University School of Medicine, New Haven, Connecticut.,Department of Neurology, Yale University School of Medicine, New Haven, Connecticut; and
| | - Yiyun Huang
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut.,Yale University PET Center, Yale University School of Medicine, New Haven, Connecticut
| | - Nabeel Nabulsi
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut.,Yale University PET Center, Yale University School of Medicine, New Haven, Connecticut
| | - Jim Ropchan
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut.,Yale University PET Center, Yale University School of Medicine, New Haven, Connecticut
| | - Richard E Carson
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut.,Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut.,Yale University PET Center, Yale University School of Medicine, New Haven, Connecticut.,Department of Biomedical Engineering, Yale School of Engineering and Applied Science, New Haven, Connecticut
| | - Stephanie S O'Malley
- Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut
| | - Kelly P Cosgrove
- Department of Radiology and Biomedical Imaging, Yale University School of Medicine, New Haven, Connecticut.,Department of Psychiatry, Yale University School of Medicine, New Haven, Connecticut.,Yale University PET Center, Yale University School of Medicine, New Haven, Connecticut.,Department of Neuroscience, Yale University School of Medicine, New Haven, Connecticut
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16
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Bini J, Sanchez-Rangel E, Gallezot JD, Naganawa M, Nabulsi N, Lim K, Najafzadeh S, Shirali A, Ropchan J, Matuskey D, Huang Y, Herold KC, Harris PE, Sherwin RS, Carson RE, Cline GW. PET Imaging of Pancreatic Dopamine D 2 and D 3 Receptor Density with 11C-(+)-PHNO in Type 1 Diabetes. J Nucl Med 2019; 61:570-576. [PMID: 31601695 DOI: 10.2967/jnumed.119.234013] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Type 1 diabetes mellitus (T1DM) has traditionally been characterized by a complete destruction of β-cell mass (BCM); however, there is growing evidence of possible residual BCM present in T1DM. Given the absence of in vivo tools to measure BCM, routine clinical measures of β-cell function (e.g., C-peptide release) may not reflect BCM. We previously demonstrated the potential utility of PET imaging with the dopamine D2 and D3 receptor agonist 3,4,4a,5,6,10b-hexahydro-2H-naphtho[1,2-b][1,4]oxazin-9-ol (11C-(+)-PHNO) to differentiate between healthy control (HC) and T1DM individuals. Methods: Sixteen individuals participated (10 men, 6 women; 9 HCs, 7 T1DMs). The average duration of diabetes was 18 ± 6 y (range, 14-30 y). Individuals underwent PET/CT scanning with a 120-min dynamic PET scan centered on the pancreas. One- and 2-tissue-compartment models were used to estimate pancreas and spleen distribution volume. Reference region approaches (spleen as reference) were also investigated. Quantitative PET measures were correlated with clinical outcome measures. Immunohistochemistry was performed to examine colocalization of dopamine receptors with endocrine hormones in HC and T1DM pancreatic tissue. Results: C-peptide release was not detectable in any T1DM individuals, whereas proinsulin was detectable in 3 of 5 T1DM individuals. Pancreas SUV ratio minus 1 (SUVR-1) (20-30 min; spleen as reference region) demonstrated a statistically significant reduction (-36.2%) in radioligand binding (HCs, 5.6; T1DMs, 3.6; P = 0.03). Age at diagnosis correlated significantly with pancreas SUVR-1 (20-30 min) (R 2 = 0.67, P = 0.025). Duration of diabetes did not significantly correlate with pancreas SUVR-1 (20-30 min) (R 2 = 0.36, P = 0.16). Mean acute C-peptide response to arginine at maximal glycemic potentiation did not significantly correlate with SUVR-1 (20-30 min) (R 2 = 0.57, P = 0.05), nor did mean baseline proinsulin (R 2 = 0.45, P = 0.10). Immunohistochemistry demonstrated colocalization of dopamine D3 receptor and dopamine D2 receptor in HCs. No colocalization of the dopamine D3 receptor or dopamine D2 receptor was seen with somatostatin, glucagon, or polypeptide Y. In a separate T1DM individual, no immunostaining was seen with dopamine D3 receptor, dopamine D2 receptor, or insulin antibodies, suggesting that loss of endocrine dopamine D3 receptor and dopamine D2 receptor expression accompanies loss of β-cell functional insulin secretory capacity. Conclusion: Thirty-minute scan durations and SUVR-1 provide quantitative outcome measures for 11C-(+)-PHNO, a dopamine D3 receptor-preferring agonist PET radioligand, to differentiate BCM in T1DM and HCs.
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Affiliation(s)
- Jason Bini
- PET Center, Yale University School of Medicine, New Haven, Connecticut
| | - Elizabeth Sanchez-Rangel
- Department of Internal Medicine, Division of Endocrinology, Yale University School of Medicine, New Haven, Connecticut; and
| | | | - Mika Naganawa
- PET Center, Yale University School of Medicine, New Haven, Connecticut
| | - Nabeel Nabulsi
- PET Center, Yale University School of Medicine, New Haven, Connecticut
| | - Keunpoong Lim
- PET Center, Yale University School of Medicine, New Haven, Connecticut
| | | | - Anupama Shirali
- PET Center, Yale University School of Medicine, New Haven, Connecticut
| | - Jim Ropchan
- PET Center, Yale University School of Medicine, New Haven, Connecticut
| | - David Matuskey
- PET Center, Yale University School of Medicine, New Haven, Connecticut
| | - Yiyun Huang
- PET Center, Yale University School of Medicine, New Haven, Connecticut
| | - Kevan C Herold
- Department of Internal Medicine, Division of Endocrinology, Yale University School of Medicine, New Haven, Connecticut; and
| | - Paul E Harris
- Department of Medicine, Division of Endocrinology, Columbia University, New York, New York
| | - Robert S Sherwin
- Department of Internal Medicine, Division of Endocrinology, Yale University School of Medicine, New Haven, Connecticut; and
| | - Richard E Carson
- PET Center, Yale University School of Medicine, New Haven, Connecticut
| | - Gary W Cline
- Department of Internal Medicine, Division of Endocrinology, Yale University School of Medicine, New Haven, Connecticut; and
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17
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Lu Y, Gallezot JD, Naganawa M, Ren S, Fontaine K, Wu J, Onofrey JA, Toyonaga T, Boutagy N, Mulnix T, Panin VY, Casey ME, Carson RE, Liu C. Data-driven voluntary body motion detection and non-rigid event-by-event correction for static and dynamic PET. Phys Med Biol 2019; 64:065002. [PMID: 30695768 DOI: 10.1088/1361-6560/ab02c2] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
PET has the potential to perform absolute in vivo radiotracer quantitation. This potential can be compromised by voluntary body motion (BM), which degrades image resolution, alters apparent tracer uptakes, introduces CT-based attenuation correction mismatch artifacts and causes inaccurate parameter estimates in dynamic studies. Existing body motion correction (BMC) methods include frame-based image-registration (FIR) approaches and real-time motion tracking using external measurement devices. FIR does not correct for motion occurring within a pre-defined frame and the device-based method is generally not practical in routine clinical use, since it requires attaching a tracking device to the patient and additional device set up time. In this paper, we proposed a data-driven algorithm, centroid of distribution (COD), to detect BM. In this algorithm, the central coordinate of the time-of-flight (TOF) bin, which can be used as a reasonable surrogate for the annihilation point, is calculated for every event, and averaged over a certain time interval to generate a COD trace. We hypothesized that abrupt changes on the COD trace in lateral direction represent BMs. After detection, BM is estimated using non-rigid image registrations and corrected through list-mode reconstruction. The COD-based BMC approach was validated using a monkey study and was evaluated against FIR using four human and one dog studies with multiple tracers. The proposed approach successfully detected BMs and yielded superior correction results over conventional FIR approaches.
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Affiliation(s)
- Yihuan Lu
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT, United States of America. Author to whom any correspondence should be addressed
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18
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Wei W, Ehlerding EB, Lan X, Luo QY, Cai W. Molecular imaging of β-cells: diabetes and beyond. Adv Drug Deliv Rev 2019; 139:16-31. [PMID: 31378283 DOI: 10.1016/j.addr.2018.06.022] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 04/27/2018] [Accepted: 06/26/2018] [Indexed: 02/09/2023]
Abstract
Since diabetes is becoming a global epidemic, there is a great need to develop early β-cell specific diagnostic techniques for this disorder. There are two types of diabetes (i.e., type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM)). In T1DM, the destruction of pancreatic β-cells leads to reduced insulin production or even absolute insulin deficiency, which consequently results in hyperglycemia. Actually, a central issue in the pathophysiology of all types of diabetes is the relative reduction of β-cell mass (BCM) and/or impairment of the function of individual β-cells. In the past two decades, scientists have been trying to develop imaging techniques for noninvasive measurement of the viability and mass of pancreatic β-cells. Despite intense scientific efforts, only two tracers for positron emission tomography (PET) and one contrast agent for magnetic resonance (MR) imaging are currently under clinical evaluation. β-cell specific imaging probes may also allow us to precisely and specifically visualize transplanted β-cells and to improve transplantation outcomes, as transplantation of pancreatic islets has shown promise in treating T1DM. In addition, some of these probes can be applied to the preoperative detection of hidden insulinomas as well. In the present review, we primarily summarize potential tracers under development for imaging β-cells with a focus on tracers for PET, SPECT, MRI, and optical imaging. We will discuss the advantages and limitations of the various imaging probes and extend an outlook on future developments in the field.
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19
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Alavi A, Werner TJ. Futility of attempts to detect and quantify beta cells by PET imaging in the pancreas: why it is time to abandon the approach. Diabetologia 2018; 61:2512-2515. [PMID: 29955934 DOI: 10.1007/s00125-018-4676-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 06/08/2018] [Indexed: 12/15/2022]
Abstract
In this commentary, we describe the limitations of positron emission tomography (PET) in visualising and characterising beta cell mass in the native pancreas in healthy individuals and those diagnosed with diabetes. Imaging with PET requires a large mass of targeted cells or other structures in the range of approximately 8-10 cm3. Since islets occupy only 1% of the pancreatic volume and are dispersed throughout the organ, it is our view that uptake of PET tracers, including [18F]fluoropropyl-(+)-dihydrotetrabenazine, in islets cannot be successfully detected by current imaging modalities. Therefore, we dispute the feasibility of PET imaging for the detection of loss of beta cells in the native pancreas in individuals with diabetes. However, we believe this novel approach can be successfully employed to visualise beta cell mass in individuals with hyperinsulinism and transplanted islets.
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Affiliation(s)
- Abass Alavi
- Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA, 19104, USA.
| | - Thomas J Werner
- Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA, 19104, USA.
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20
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Cline GW, McCarthy TJ, Carson RE, Calle RA. Clinical and scientific value in the pursuit of quantification of beta cells in the pancreas by PET imaging. Diabetologia 2018; 61:2671-2673. [PMID: 30136144 PMCID: PMC6219921 DOI: 10.1007/s00125-018-4718-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Accepted: 08/01/2018] [Indexed: 12/17/2022]
Affiliation(s)
- Gary W Cline
- Yale University, 801 Howard Avenue, PO Box 208048, New Haven, CT, 06520, USA.
| | | | - Richard E Carson
- Yale University, 801 Howard Avenue, PO Box 208048, New Haven, CT, 06520, USA
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