title: Florbetapir F18 PET Amyloid Neuroimaging and Characteristics in Patients With Mild and Moderate Alzheimer Dementia.
abstract: BACKGROUND
  Clinical diagnosis of Alzheimer disease (AD) is challenging, with a 70.9%-87.3% sensitivity and 44.3%-70.8% specificity, compared with autopsy diagnosis. Florbetapir F18 positron emission tomography (FBP-PET) estimates beta-amyloid plaque density antemortem.
  
  
  METHODS
  Of 2052 patients (≥55 years old) clinically diagnosed with mild or moderate AD dementia from 2 solanezumab clinical trials, 390 opted to participate in a FBP-PET study addendum. We analyzed baseline prerandomization characteristics.
  
  
  RESULTS
  A total of 22.4% had negative FBP-PET scans, whereas 72.5% of mild and 86.9% of moderate AD patients had positive results. No baseline clinical variable reliably differentiated negative from positive FBP-PET scan groups.
  
  
  CONCLUSIONS
  These data confirm the challenges of correctly diagnosing AD without using biomarkers. FBP-PET can aid AD dementia differential diagnosis by detecting amyloid pathology antemortem, even when the diagnosis of AD is made by expert clinicians.
authors.affiliation: IU Health Physicians Group, Department of Psychiatry, Indiana University School of Medicine Collaboration, Indiana University Health, Indianapolis, IN.
authors.forename: Elisabeth K
authors.initials: EK
authors.lastname: Degenhardt
authors.affiliation: Lilly USA, LLC, Neurosciences, Indianapolis, IN.
authors.forename: Michael M
authors.initials: MM
authors.lastname: Witte
authors.affiliation: Lilly Research Laboratories, Lilly Corporate Center, Indianapolis, IN.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Case
authors.affiliation: Lilly Research Laboratories, Lilly Corporate Center, Indianapolis, IN.
authors.forename: Peng
authors.initials: P
authors.lastname: Yu
authors.affiliation: Lilly USA, LLC, Neurosciences, Indianapolis, IN; Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN.
authors.forename: David B
authors.initials: DB
authors.lastname: Henley
authors.affiliation: Lilly USA, LLC, Neurosciences, Indianapolis, IN. Electronic address: hochstetler_helen_m@lilly.com.
authors.forename: Helen M
authors.initials: HM
authors.lastname: Hochstetler
authors.affiliation: inVentiv Health, LLC, Burlington, MA.
authors.forename: Deborah N
authors.initials: DN
authors.lastname: D'Souza
authors.affiliation: Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN.
authors.forename: Paula T
authors.initials: PT
authors.lastname: Trzepacz
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000000981:diagnostic imaging*; D000682:Amyloid / Q000378:metabolism*; D000814:Aniline Compounds; D001344:Autopsy; D001921:Brain / Q000000981:diagnostic imaging*; D005026:Ethylene Glycols; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D059906:Neuroimaging; D049268:Positron-Emission Tomography; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index
chemical_list: D000682:Amyloid; D000814:Aniline Compounds; D005026:Ethylene Glycols; D019788:Fluorodeoxyglucose F18; C545186:florbetapir