Florbetapir F18 PET Amyloid Neuroimaging and Characteristics in Patients With Mild and Moderate Alzheimer Dementia

• Published in: Psychosomatics (Washington, D.C.) Vol. 57; no. 2; pp. 208 - 216
• Main Authors: Degenhardt, Elisabeth K., Witte, Michael M., Case, Michael G., Yu, Peng, Henley, David B., Hochstetler, Helen M., D’Souza, Deborah N., Trzepacz, Paula T.
• Format: Journal Article
• Language: English
• Published: England Elsevier Inc 01.03.2016
• Subjects: Aged; Alzheimer Disease - diagnostic imaging; Amyloid - metabolism; Aniline Compounds; Autopsy; Brain - diagnostic imaging; Ethylene Glycols; Female; Fluorodeoxyglucose F18; Humans; Internal Medicine; Male; Neuroimaging; Positron-Emission Tomography; Psychiatry; Reproducibility of Results; Sensitivity and Specificity; Severity of Illness Index
• ISSN: 0033-3182; 1545-7206; 1545-7206
• DOI: 10.1016/j.psym.2015.12.002

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. 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. 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. 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.