1
|
Wang YTT, Rosa-Neto P, Gauthier S. Advanced brain imaging for the diagnosis of Alzheimer disease. Curr Opin Neurol 2023; 36:481-490. [PMID: 37639461 DOI: 10.1097/wco.0000000000001198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
PURPOSE OF REVIEW The purpose is to review the latest advances of brain imaging for the diagnosis of Alzheimer disease (AD). RECENT FINDINGS Brain imaging techniques provide valuable and complementary information to support the diagnosis of Alzheimer disease in clinical and research settings. The recent FDA accelerated approvals of aducanumab, lecanemab and donanemab made amyloid-PET critical in helping determine the optimal window for anti-amyloid therapeutic interventions. Tau-PET, on the other hand, is considered of key importance for the tracking of disease progression and for monitoring therapeutic interventions in clinical trials. PET imaging for microglial activation, astrocyte reactivity and synaptic degeneration are still new techniques only used in the research field, and more studies are needed to validate their use in the clinical diagnosis of AD. Finally, artificial intelligence has opened new prospective in the early detection of AD using MRI modalities. SUMMARY Brain imaging techniques using PET improve our understanding of the different AD-related pathologies and their relationship with each other along the course of disease. With more robust validation, machine learning and deep learning algorithms could be integrated with neuroimaging modalities to serve as valuable tools for clinicians to make early diagnosis and prognosis of AD.
Collapse
|
2
|
Wagatsuma K, Miwa K, Akamatsu G, Yamao T, Kamitaka Y, Sakurai M, Fujita N, Hanaoka K, Matsuda H, Ishii K. Toward standardization of tau PET imaging corresponding to various tau PET tracers: a multicenter phantom study. Ann Nucl Med 2023; 37:494-503. [PMID: 37243882 DOI: 10.1007/s12149-023-01847-8] [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] [Received: 03/20/2023] [Accepted: 05/17/2023] [Indexed: 05/29/2023]
Abstract
OBJECTIVE Tau positron emission tomography (PET) imaging is a recently developed non-invasive tool that can detect the density and extension of tau neurofibrillary tangles. Tau PET tracers have been validated to harmonize and accelerate their development and implementation in clinical practice. Whereas standard protocols including injected dose, uptake time, and duration have been determined for tau PET tracers, reconstruction parameters have not been standardized. The present study conducted phantom experiments based on tau pathology to standardize quantitative tau PET imaging parameters and optimize reconstruction conditions of PET scanners at four Japanese sites according to the results of phantom experiments. METHODS The activity of 4.0 and 2.0 kBq/mL for Hoffman 3D brain and cylindrical phantoms, respectively, was estimated from published studies of brain activity using [18F]flortaucipir, [18F]THK5351, and [18F]MK6240. We developed an original tau-specific volume of interest template for the brain based on pathophysiological tau distribution in the brain defined as Braak stages. We acquired brain and cylindrical phantom images using four PET scanners. Iteration numbers were determined as contrast and recover coefficients (RCs) in gray (GM) and white (WM) matter, and the magnitude of the Gaussian filter was determined from image noise. RESULTS Contrast and RC converged at ≥ 4 iterations, the error rates of RC for GM and WM were < 15% and 1%, respectively, and noise was < 10% in Gaussian filters of 2-4 mm in images acquired using the four scanners. Optimizing the reconstruction conditions for phantom tau PET images acquired by each scanner improved contrast and image noise. CONCLUSIONS The phantom activity was comprehensive for first- and second-generation tau PET tracers. The mid-range activity that we determined could be applied to later tau PET tracers. We propose an analytical tau-specific VOI template based on tau pathophysiological changes in patients with AD to standardize tau PET imaging. Phantom images reconstructed under the optimized conditions for tau PET imaging achieved excellent image quality and quantitative accuracy.
Collapse
Affiliation(s)
- Kei Wagatsuma
- School of Allied Health Sciences, Kitasato University, 1-15-1 Kitazato, Minami-Ku, Sagamihara, Kanagawa, 252-0373, Japan.
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2, Sakae-Cho, Itabashi-Ku, Tokyo, 173-0015, Japan.
| | - Kenta Miwa
- Department of Radiological Sciences, School of Health Sciences, Fukushima Medical University, Fukushima City, Fukushima, 960-1295, Japan
| | - Go Akamatsu
- Department of Advanced Nuclear Medicine Sciences, Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology (QST), 4-9-1 Anagawa, Inage-Ku, Chiba, 263-8555, Japan
| | - Tensho Yamao
- Department of Radiological Sciences, School of Health Sciences, Fukushima Medical University, Fukushima City, Fukushima, 960-1295, Japan
| | - Yuto Kamitaka
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2, Sakae-Cho, Itabashi-Ku, Tokyo, 173-0015, Japan
| | - Minoru Sakurai
- Clinical Imaging Center for Healthcare, Nippon Medical School, 1-12-15, Sendagi, Bunkyo-Ku, Tokyo, 113-0022, Japan
| | - Naotoshi Fujita
- Department of Radiological Technology, Nagoya University Hospital, 65 Tsurumai-Cho, Showa-Ku, Nagoya, 466-8560, Japan
| | - Kohei Hanaoka
- Division of Positron Emission Tomography, Institute of Advanced Clinical Medicine, Kindai University, 377-2 Onohigashi, Osakasayama, Osaka, 589-8511, Japan
| | - Hiroshi Matsuda
- Department of Biofunctional Imaging, Fukushima Medical University, 1 Hikarigaoka, Fukushima City, Fukushima, 960-1295, Japan
- Drug Discovery and Cyclotron Research Center, Southern Tohoku Research Institute for Neuroscience, 7-115, Yatsuyamada, Koriyama, 963-8052, Japan
| | - Kenji Ishii
- Research Team for Neuroimaging, Tokyo Metropolitan Institute of Gerontology, 35-2, Sakae-Cho, Itabashi-Ku, Tokyo, 173-0015, Japan
| |
Collapse
|
3
|
Kang JM, Shin JH, Kim WR, Seo S, Seo H, Lee SY, Park KH, Na DL, Okamura N, Seong JK, Noh Y. Effects of the APOEɛ4 Allele on the Relationship Between Tau and Amyloid-β in Early- and Late-Onset Alzheimer's Disease. J Alzheimers Dis 2023; 94:1233-1246. [PMID: 37393505 DOI: 10.3233/jad-230339] [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] [Indexed: 07/03/2023]
Abstract
BACKGROUND Little is known regarding the differential effects of the apolipoprotein E (APOE) ɛ4 on the regional topography of amyloid and tau in patients with both early-onset (EOAD) and late-onset Alzheimer's disease (LOAD). OBJECTIVE To compare the distribution and association of tau, amyloid, and cortical thickness among groups classified by the presence of APOEɛ4 allele and onset age. METHODS A total of 165 participants including 54 EOAD patients (29 ɛ4-; 25 ɛ4+), 45 LOAD patients (21 ɛ4-; 24 ɛ4+), and 66 age-matched controls underwent 3T MRI, 18F-THK5351 (THK) and 18F-flutemetamol (FLUTE) PET scans, APOE genotyping, and neuropsychological tests. Data for voxel-wise and standardized uptake values from PET scans were analyzed in the context of APOE and age at onset. RESULTS EOAD ɛ4- patients showed greater THK retention in the association cortices, whereas their EOAD ɛ4+ counterparts had more retention in medial temporal areas. THK topography of LOAD ɛ4+ was similar to EOAD ɛ4 + . THK correlated positively with FLUTE and conversely with mean cortical thickness, being lowest in EOAD ɛ4-, highest in LOAD ɛ4-, and modest in ɛ4+ groups. Even in the APOEɛ4+ groups, THK tended to correlate with FLUTE and mean cortical thickness in the inferior parietal region in EOAD and in the medial temporal region in LOAD. LOAD ɛ4- manifested with prevalent small vessel disease markers and the lowest correlation between THK retention and cognition. CONCLUSION Our observations suggest the differential effects of the APOEɛ4 on the relationship between tau and amyloid in EOAD and LOAD.
Collapse
Affiliation(s)
- Jae Myeong Kang
- Department of Psychiatry, Gil Medical Center, Gachon University College of Medicine, Incheon, Republic of Korea
| | - Jeong-Hyeon Shin
- School of Biomedical Engineering, Korea University, Seoul, Republic of Korea
- Bio Medical Research Center, Bio Medical & Health Division, Korea Testing Laboratory, Daegu, Republic of Korea
| | - Woo-Ram Kim
- Neuroscience Research Institute, Gachon University, Incheon, Republic of Korea
| | - Seongho Seo
- Neuroscience Research Institute, Gachon University, Incheon, Republic of Korea
| | - Haeun Seo
- Neuroscience Research Institute, Gachon University, Incheon, Republic of Korea
| | - Sang-Yoon Lee
- Department of Neuroscience, College of Medicine, Gachon University, Incheon, Republic of Korea
| | - Kee Hyung Park
- Department of Neurology, Gil Medical Center, Gachon University College of Medicine, Incheon, Republic of Korea
| | - Duk L Na
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine Seoul, Republic of Korea; Happymind Clinic, Seoul, Republic of Korea
| | - Nobuyuki Okamura
- Division of Pharmacology, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, Sendai, Japan
| | - Joon-Kyoung Seong
- School of Biomedical Engineering, Korea University, Seoul, Republic of Korea
- Department of Artificial Intelligence, Korea University, Seoul, Republic of Korea
| | - Young Noh
- Department of Neurology, Gil Medical Center, Gachon University College of Medicine, Incheon, Republic of Korea
- Department of Health Science and Technology, GAIHST, Gachon University, Incheon, Republic of Korea
| |
Collapse
|
4
|
Groot C, Villeneuve S, Smith R, Hansson O, Ossenkoppele R. Tau PET Imaging in Neurodegenerative Disorders. J Nucl Med 2022; 63:20S-26S. [PMID: 35649647 DOI: 10.2967/jnumed.121.263196] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 03/09/2022] [Indexed: 11/16/2022] Open
Abstract
The advent of PET ligands that bind tau pathology has enabled the quantification and visualization of tau pathology in aging and in Alzheimer disease (AD). There is strong evidence from neuropathologic studies that the most widely used tau PET tracers (i.e., 18F-flortaucipir, 18F-MK6240, 18F-RO948, and 18F-PI2620) bind tau aggregates formed in AD in the more advanced (i.e., ≥IV) Braak stages. However, tracer binding in most non-AD tauopathies is weaker and overlaps to a large extent with known off-target binding regions, limiting the quantification and visualization of non-AD tau pathology in vivo. Off-target binding is generally present in the substantia nigra, basal ganglia, pituitary, choroid plexus, longitudinal sinuses, meninges, or skull in a tracer-specific manner. Most cross-sectional studies use the inferior aspect of the cerebellar gray matter as a reference region, whereas for longitudinal analyses, an eroded white matter reference region is sometimes selected. No consensus has yet been reached on whether to use partial-volume correction of tau PET data. Although an increased neocortical tau PET signal is rare in cognitively unimpaired individuals, even in amyloid-β-positive cases, such a signal holds important prognostic information because preliminary data suggest that an elevated tau PET signal predicts cognitive decline over time. Also, in symptomatic stages of AD (i.e., mild cognitive impairment or AD dementia), tau PET shows great potential as a prognostic marker because an elevated baseline tau PET retention forecasts future cognitive decline and brain atrophy. For differential diagnostic use, the primary utility of tau PET is to differentiate AD dementia from other neurodegenerative diseases, as is in line with the conditions for the approval of 18F-flortaucipir by the U.S. Food and Drug Administration for clinical use. The differential diagnostic performance drops substantially at the mild-cognitive-impairment stage of AD, and there is no sufficient evidence for detection of sporadic non-AD primary tauopathies at the individual level for any of the currently available tau PET tracers. In conclusion, while the field is currently addressing outstanding methodologic issues, tau PET is gradually moving toward clinical application as a diagnostic and possibly prognostic marker in dementia expert centers and as a tool for selecting participants, assessing target engagement, and monitoring treatment effects in clinical trials.
Collapse
Affiliation(s)
- Colin Groot
- Clinical Memory Research Unit, Lund University, Lund, Sweden.,Alzheimer Center Amsterdam, Department of Neurology, Amsterdam Neuroscience, Amsterdam UMC, Location VUMC, Amsterdam, The Netherlands
| | - Sylvia Villeneuve
- Department of Psychiatry, Faculty of Medicine, McGill University, Montreal, Canada.,Douglas Mental Health University Institute, Montreal, Canada.,McConnell Brain Imaging Centre, Montreal Neurological Institute, Montreal, Canada; and
| | - Ruben Smith
- Clinical Memory Research Unit, Lund University, Lund, Sweden.,Memory Clinic, Skåne University Hospital, Malmö, Sweden
| | - Oskar Hansson
- Clinical Memory Research Unit, Lund University, Lund, Sweden.,Memory Clinic, Skåne University Hospital, Malmö, Sweden
| | - Rik Ossenkoppele
- Clinical Memory Research Unit, Lund University, Lund, Sweden; .,Alzheimer Center Amsterdam, Department of Neurology, Amsterdam Neuroscience, Amsterdam UMC, Location VUMC, Amsterdam, The Netherlands
| |
Collapse
|
5
|
Ni R, Nitsch RM. Recent Developments in Positron Emission Tomography Tracers for Proteinopathies Imaging in Dementia. Front Aging Neurosci 2022; 13:751897. [PMID: 35046791 PMCID: PMC8761855 DOI: 10.3389/fnagi.2021.751897] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 11/17/2021] [Indexed: 12/15/2022] Open
Abstract
An early detection and intervention for dementia represent tremendous unmet clinical needs and priorities in society. A shared feature of neurodegenerative diseases causing dementia is the abnormal accumulation and spreading of pathological protein aggregates, which affect the selective vulnerable circuit in a disease-specific pattern. The advancement in positron emission tomography (PET) biomarkers has accelerated the understanding of the disease mechanism and development of therapeutics for Alzheimer's disease and Parkinson's disease. The clinical utility of amyloid-β PET and the clinical validity of tau PET as diagnostic biomarker for Alzheimer's disease continuum have been demonstrated. The inclusion of biomarkers in the diagnostic criteria has introduced a paradigm shift that facilitated the early and differential disease diagnosis and impacted on the clinical management. Application of disease-modifying therapy likely requires screening of patients with molecular evidence of pathological accumulation and monitoring of treatment effect assisted with biomarkers. There is currently still a gap in specific 4-repeat tau imaging probes for 4-repeat tauopathies and α-synuclein imaging probes for Parkinson's disease and dementia with Lewy body. In this review, we focused on recent development in molecular imaging biomarkers for assisting the early diagnosis of proteinopathies (i.e., amyloid-β, tau, and α-synuclein) in dementia and discussed future perspectives.
Collapse
Affiliation(s)
- Ruiqing Ni
- Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland
- Institute for Biomedical Engineering, ETH & University of Zurich, Zurich, Switzerland
| | - Roger M. Nitsch
- Institute for Regenerative Medicine, University of Zurich, Zurich, Switzerland
| |
Collapse
|
6
|
Garibotto V, Boccardi M, Chiti A, Frisoni GB. Molecular imaging and fluid biomarkers of Alzheimer's disease neuropathology: an opportunity for integrated diagnostics. Eur J Nucl Med Mol Imaging 2021; 48:2067-2069. [PMID: 33688995 DOI: 10.1007/s00259-020-05116-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Valentina Garibotto
- NIMTlab - Neuroimaging and Innovative Molecular Tracers Laboratory, University of Geneva, Geneva, Switzerland. .,Nuclear Medicine and Molecular Division, University Hospitals of Geneva, Rue Gabrielle-Perret-Gentil 4, 1205, Geneva, Switzerland.
| | - Marina Boccardi
- German Center for Neurodegenerative Diseases (DZNE) Rostock-Greifswald, Rostock, Germany
| | - Arturo Chiti
- Department of Biomedical Sciences, Humanitas University, Milan, Italy.,Humanitas Clinical and Research Center, IRCCS, Milan, Italy
| | - Giovanni B Frisoni
- Memory Clinic, University Hospital, Geneva, Switzerland.,LANVIE - Laboratory of Neuroimaging of Aging, University of Geneva, Geneva, Switzerland
| |
Collapse
|
7
|
Boccardi M, Dodich A, Albanese E, Gayet-Ageron A, Festari C, Ashton NJ, Bischof GN, Chiotis K, Leuzy A, Wolters EE, Walter MA, Rabinovici GD, Carrillo M, Drzezga A, Hansson O, Nordberg A, Ossenkoppele R, Villemagne VL, Winblad B, Frisoni GB, Garibotto V. The strategic biomarker roadmap for the validation of Alzheimer's diagnostic biomarkers: methodological update. Eur J Nucl Med Mol Imaging 2021; 48:2070-2085. [PMID: 33688996 PMCID: PMC8175304 DOI: 10.1007/s00259-020-05120-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 11/15/2020] [Indexed: 12/11/2022]
Abstract
Background The 2017 Alzheimer’s disease (AD) Strategic Biomarker Roadmap (SBR) structured the validation of AD diagnostic biomarkers into 5 phases, systematically assessing analytical validity (Phases 1–2), clinical validity (Phases 3–4), and clinical utility (Phase 5) through primary and secondary Aims. This framework allows to map knowledge gaps and research priorities, accelerating the route towards clinical implementation. Within an initiative aimed to assess the development of biomarkers of tau pathology, we revised this methodology consistently with progress in AD research. Methods We critically appraised the adequacy of the 2017 Biomarker Roadmap within current diagnostic frameworks, discussed updates at a workshop convening the Alzheimer’s Association and 8 leading AD biomarker research groups, and detailed the methods to allow consistent assessment of aims achievement for tau and other AD diagnostic biomarkers. Results The 2020 update applies to all AD diagnostic biomarkers. In Phases 2–3, we admitted a greater variety of study designs (e.g., cross-sectional in addition to longitudinal) and reference standards (e.g., biomarker confirmation in addition to clinical progression) based on construct (in addition to criterion) validity. We structured a systematic data extraction to enable transparent and formal evidence assessment procedures. Finally, we have clarified issues that need to be addressed to generate data eligible to evidence-to-decision procedures. Discussion This revision allows for more versatile and precise assessment of existing evidence, keeps up with theoretical developments, and helps clinical researchers in producing evidence suitable for evidence-to-decision procedures. Compliance with this methodology is essential to implement AD biomarkers efficiently in clinical research and diagnostics.
Collapse
Affiliation(s)
- Marina Boccardi
- German Center for Neurodegenerative Diseases DZNE-Standort Rostock/Greifswald, Gehlsheimer Str. 20, 18147, Rostock, Germany.
- LANVIE - Laboratory of Neuroimaging of Aging, University of Geneva, Geneva, Switzerland.
| | - Alessandra Dodich
- Center for Neurocognitive Rehabilitation (CeRiN), CIMeC, University of Trento, Trento, Italy
- NIMTlab - Neuroimaging and Innovative Molecular Tracers Laboratory, University of Geneva, Geneva, Switzerland
| | - Emiliano Albanese
- USI - Università della Svizzera Italiana, Institute of Public Health (IPH), Lugano, Switzerland
| | - Angèle Gayet-Ageron
- Division of Clinical Epidemiology, Department of Health and Community Medicine, University of Geneva & University Hospitals of Geneva, Geneva, Switzerland
| | - Cristina Festari
- LANE - Laboratory of Alzheimer's Neuroimaging and Epidemiology, IRCCS Istituto Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy
| | - Nicholas J Ashton
- Wallenberg Centre for Molecular and Translational Medicine, University of Gothenburg, Gothenburg, Sweden
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience & Physiology, The Sahlgrenska Academy at The University of Gothenburg, Molndal, Sweden
- NIHR Biomedical Research Centre for Mental Health and Biomedical Research Unit for Dementia at South London and Maudsley NHS Foundation, London, UK
- Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Gérard N Bischof
- Department of Nuclear Medicine, University Hospital Cologne, Cologne, Germany
| | - Konstantinos Chiotis
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
- Theme Neurology, Karolinska University Hospital, Stockholm, Sweden
| | - Antoine Leuzy
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
| | - Emma E Wolters
- Alzheimer Center Amsterdam, Department of Neurology, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam UMC, Amsterdam, Netherlands
| | - Martin A Walter
- Nuclear Medicine and Molecular Division, Geneva Medical Hospital, Geneva, Switzerland
| | - Gil D Rabinovici
- Departments of Neurology, Radiology & Biomedical Imaging, University of California, San Francisco, CA, USA
| | | | - Alexander Drzezga
- Faculty of Medicine, University of Cologne, Cologne, Germany
- German Center for Neurodegenerative Diseases (DZNE), Bonn/Cologne, Germany
- Molecular Organization of the Brain, Research Center Jülich, Institute of Neuroscience and Medicine (INM-2), Julich, Germany
| | - Oskar Hansson
- Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Lund University, Lund, Sweden
- Memory Clinic, Skåne University Hospital, Malmo, Sweden
| | - Agneta Nordberg
- Division of Clinical Geriatrics, Center for Alzheimer Research, Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
- Karolinska University Hospital, Theme Aging, Geriatric Clinic, Huddinge, Sweden
| | - Rik Ossenkoppele
- Alzheimer Center Amsterdam, Department of Neurology, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam UMC, Amsterdam, Netherlands
- Department of Clinical Memory Research, Lund University, Lund, Sweden
| | - Victor L Villemagne
- Department of Molecular Imaging & Therapy, Austin Health, Melbourne, VIC, Australia
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsilvania, USA
| | - Bengt Winblad
- Karolinska University Hospital, Theme Aging, Geriatric Clinic, Huddinge, Sweden
- Department of Neurobiology, Care Sciences and Society, Division of Neurogeriatrics, Karolinska Institutet, Stockholm, Sweden
| | - Giovanni B Frisoni
- LANVIE - Laboratory of Neuroimaging of Aging, University of Geneva, Geneva, Switzerland
- Memory Clinic, University Hospital, Geneva, Switzerland
| | - Valentina Garibotto
- NIMTlab - Neuroimaging and Innovative Molecular Tracers Laboratory, University of Geneva, Geneva, Switzerland
- Nuclear Medicine and Molecular Division, Geneva Medical Hospital, Geneva, Switzerland
| |
Collapse
|
8
|
Clinical validity of increased cortical uptake of [ 18F]flortaucipir on PET as a biomarker for Alzheimer's disease in the context of a structured 5-phase biomarker development framework. Eur J Nucl Med Mol Imaging 2021; 48:2097-2109. [PMID: 33547556 PMCID: PMC8175307 DOI: 10.1007/s00259-020-05118-w] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Accepted: 11/15/2020] [Indexed: 12/14/2022]
Abstract
PURPOSE In 2017, the Geneva Alzheimer's disease (AD) Biomarker Roadmap initiative adapted the framework of the systematic validation of oncological diagnostic biomarkers to AD biomarkers, with the aim to accelerate their development and implementation in clinical practice. With this work, we assess the maturity of [18F]flortaucipir PET and define its research priorities. METHODS The level of maturity of [18F]flortaucipir was assessed based on the AD Biomarker Roadmap. The framework assesses analytical validity (phases 1-2), clinical validity (phases 3-4), and clinical utility (phase 5). RESULTS The main aims of phases 1 (rationale for use) and 2 (discriminative ability) have been achieved. [18F]Flortaucipir binds with high affinity to paired helical filaments of tau and has favorable kinetic properties and excellent discriminative accuracy for AD. The majority of secondary aims of phase 2 were fully achieved. Multiple studies showed high correlations between ante-mortem [18F]flortaucipir PET and post-mortem tau (as assessed by histopathology), and also the effects of covariates on tracer binding are well studied. The aims of phase 3 (early detection ability) were only partially or preliminarily achieved, and the aims of phases 4 and 5 were not achieved. CONCLUSION Current literature provides partial evidence for clinical utility of [18F]flortaucipir PET. The aims for phases 1 and 2 were mostly achieved. Phase 3 studies are currently ongoing. Future studies including representative MCI populations and a focus on healthcare outcomes are required to establish full maturity of phases 4 and 5.
Collapse
|