title: Diagnostic impact of [18F]flutemetamol PET in early-onset dementia.
abstract: BACKGROUND
  Early-onset dementia patients often present with atypical clinical symptoms, hampering an accurate clinical diagnosis. The purpose of the present study was to assess the diagnostic impact of the amyloid-positron emission tomography (PET) imaging agent [18F]flutemetamol in early-onset dementia patients, in terms of change in (confidence in) diagnosis and patient management plan.
  
  
  METHODS
  This prospective bi-center study included 211 patients suspected of early-onset dementia who visited a tertiary memory clinic. Patients were eligible with Mini Mental State Examination ≥ 18 and age at diagnosis ≤ 70 years and in whom the diagnostic confidence was <90% after routine diagnostic work-up. All patients underwent [18F]flutemetamol PET, which was interpreted as amyloid-negative or amyloid-positive based on visual rating. Before and after disclosing the PET results, we assessed the diagnostic confidence (using a visual analog scale of 0-100%) and clinical diagnosis. The impact of [18F]flutemetamol PET on the patient management plan was also evaluated.
  
  
  RESULTS
  [18F]flutemetamol PET scans were positive in 133 out of 211 (63%) patients, of whom 110 out of 144 (76%) patients had a pre-PET Alzheimer's disease (AD) diagnosis and 23 out of 67 (34%) patients had a non-AD diagnosis. After disclosure of PET results, 41/211 (19%) diagnoses changed. Overall, diagnostic confidence increased from 69 ± 12% to 88 ± 15% after disclosing PET results (P < 0.001; in 87% of patients). In 79 (37%) patients, PET results led to a change in patient management and predominantly the initiation of AD medication when PET showed evidence for amyloid pathology.
  
  
  CONCLUSIONS
  [18F]flutemetamol PET changed clinical diagnosis, increased overall diagnostic confidence, and altered the patient management plan. Our results suggest that amyloid PET may have added value over the standardized diagnostic work-up in early-onset dementia patients with uncertain clinical diagnosis. This study provides evidence for the recommendations put forward in the appropriate use criteria for amyloid PET in clinical practice.
  
  
  BACKGROUND
  Nederlands Trial Register NTR3743 . Registered 7 December 2012.
authors.affiliation: Alzheimer Center & Department of Neurology, Amsterdam Neuroscience, VU University Medical Center, PO Box 7057, 1007 MB, Amsterdam, The Netherlands. m.zwan@vumc.nl.|Department of Radiology & Nuclear Medicine, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, The Netherlands. m.zwan@vumc.nl.
authors.forename: Marissa D
authors.initials: MD
authors.lastname: Zwan
authors.affiliation: Alzheimer Center & Department of Neurology, Amsterdam Neuroscience, VU University Medical Center, PO Box 7057, 1007 MB, Amsterdam, The Netherlands.
authors.forename: Femke H
authors.initials: FH
authors.lastname: Bouwman
authors.affiliation: Alzheimer Center & Department of Neurology, Amsterdam Neuroscience, VU University Medical Center, PO Box 7057, 1007 MB, Amsterdam, The Netherlands.
authors.forename: Elles
authors.initials: E
authors.lastname: Konijnenberg
authors.affiliation: Alzheimer Center & Department of Neurology, Amsterdam Neuroscience, VU University Medical Center, PO Box 7057, 1007 MB, Amsterdam, The Netherlands.|Department of Epidemiology & Biostatistics, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Wiesje M
authors.initials: WM
authors.lastname: van der Flier
authors.affiliation: Department of Radiology & Nuclear Medicine, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Adriaan A
authors.initials: AA
authors.lastname: Lammertsma
authors.affiliation: School for Mental Health and Neuroscience, Alzheimer Centre Limburg, European Graduate School of Neuroscience EURON, Maastricht University, Maastricht, The Netherlands.
authors.forename: Frans R J
authors.initials: FR
authors.lastname: Verhey
authors.affiliation: School for Mental Health and Neuroscience, Alzheimer Centre Limburg, European Graduate School of Neuroscience EURON, Maastricht University, Maastricht, The Netherlands.
authors.forename: Pauline
authors.initials: P
authors.lastname: Aalten
authors.affiliation: Department of Radiology & Nuclear Medicine, Amsterdam Neuroscience, VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Bart N M
authors.initials: BN
authors.lastname: van Berckel
authors.affiliation: Alzheimer Center & Department of Neurology, Amsterdam Neuroscience, VU University Medical Center, PO Box 7057, 1007 MB, Amsterdam, The Netherlands.
authors.forename: Philip
authors.initials: P
authors.lastname: Scheltens
mesh_terms: D017668:Age of Onset; D000368:Aged; D000814:Aniline Compounds; D052160:Benzothiazoles; D001921:Brain / Q000000981:diagnostic imaging*; D003704:Dementia / Q000000981:diagnostic imaging*; D005260:Female; D005462:Fluorine Radioisotopes; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D019275:Radiopharmaceuticals
chemical_list: D000814:Aniline Compounds; D052160:Benzothiazoles; D005462:Fluorine Radioisotopes; D019275:Radiopharmaceuticals; C581552:flutemetamol
keywords: Alzheimer’s disease; Amyloid; Clinical practice; Dementia; Diagnostic impact; Imaging; Positron emission tomography