Federico Massa1, Lucia Farotti2, Paolo Eusebi3,4, Elisabetta Capello5, Massimo E Dottorini6, Cristina Tranfaglia6, Matteo Bauckneht7, Silvia Morbelli7,8, Flavio Nobili1,5, Lucilla Parnetti2. 1. Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, Genoa, Italy. 2. Center for Memory Disorders and Laboratory of Clinical Neurochemistry, Neurology Clinic, University of Perugia, Perugia, Italy. 3. Section of Neurology, Department of Medicine, University of Perugia, Perugia, Italy. 4. Health Planning Service, Department of Epidemiology, Regional Health Authority of Umbria, Perugia, Italy. 5. Neurology Clinic, IRCCS Ospedale Policlinico San Martino, Genoa, Italy. 6. Nuclear Medicine Unit, "S. Maria della Misericordia" Hospital, Perugia, Italy. 7. Nuclear Medicine Unit, IRCCS Ospedale Policlinico San Martino, Genoa, Italy. 8. Department of Health Sciences (DISSAL), University of Genoa, Genoa, Italy.
Abstract
BACKGROUND: In Alzheimer's disease (AD) diagnosis, both cerebrospinal fluid (CSF) biomarkers and FDG-PET sometimes give inconclusive results. OBJECTIVE: To evaluate the incremental diagnostic value of FDG-PET over CSF biomarkers, and vice versa, in patients with mild cognitive impairment (MCI) and suspected AD, in which the first biomarker resulted inconclusive. METHODS: A consecutive series of MCI patients was retrospectively selected from two Memory Clinics where, as per clinical routine, either the first biomarker choice is FDG-PET and CSF biomarkers are only used in patients with uninformative FDG-PET, or vice versa. We defined criteria of uncertainty in interpretation of FDG-PET and CSF biomarkers, according to current evidence. The final diagnosis was established according to clinical-neuropsychological follow-up of at least one year (mean 4.4±2.2). RESULTS: When CSF was used as second biomarker after FDG-PET, 14 out of 36 (39%) received informative results. Among these 14 patients, 11 (79%) were correctly classified with respect to final diagnosis, thus with a relative incremental value of CSF over FDG-PET of 30.6%. When FDG-PET was used as second biomarker, 26 out of 39 (67%) received informative results. Among these 26 patients, 15 (58%) were correctly classified by FDG-PET with respect to final diagnosis, thus with a relative incremental value over CSF of 38.5%. CONCLUSION: Our real-world data confirm the added values of FDG-PET (or CSF) in a diagnostic pathway where CSF (or FDG-PET) was used as first biomarkers in suspected AD. These findings should be replicated in larger studies with prospective enrolment according to a Phase III design.
BACKGROUND: In Alzheimer's disease (AD) diagnosis, both cerebrospinal fluid (CSF) biomarkers and FDG-PET sometimes give inconclusive results. OBJECTIVE: To evaluate the incremental diagnostic value of FDG-PET over CSF biomarkers, and vice versa, in patients with mild cognitive impairment (MCI) and suspected AD, in which the first biomarker resulted inconclusive. METHODS: A consecutive series of MCI patients was retrospectively selected from two Memory Clinics where, as per clinical routine, either the first biomarker choice is FDG-PET and CSF biomarkers are only used in patients with uninformative FDG-PET, or vice versa. We defined criteria of uncertainty in interpretation of FDG-PET and CSF biomarkers, according to current evidence. The final diagnosis was established according to clinical-neuropsychological follow-up of at least one year (mean 4.4±2.2). RESULTS: When CSF was used as second biomarker after FDG-PET, 14 out of 36 (39%) received informative results. Among these 14 patients, 11 (79%) were correctly classified with respect to final diagnosis, thus with a relative incremental value of CSF over FDG-PET of 30.6%. When FDG-PET was used as second biomarker, 26 out of 39 (67%) received informative results. Among these 26 patients, 15 (58%) were correctly classified by FDG-PET with respect to final diagnosis, thus with a relative incremental value over CSF of 38.5%. CONCLUSION: Our real-world data confirm the added values of FDG-PET (or CSF) in a diagnostic pathway where CSF (or FDG-PET) was used as first biomarkers in suspected AD. These findings should be replicated in larger studies with prospective enrolment according to a Phase III design.
Authors: Le Gjerum; Birgitte Bo Andersen; Marie Bruun; Anja Hviid Simonsen; Otto Mølby Henriksen; Ian Law; Steen Gregers Hasselbalch; Kristian Steen Frederiksen Journal: PLoS One Date: 2021-03-12 Impact factor: 3.240