Florbetaben PET imaging to detect amyloid beta plaques in Alzheimer's disease: Phase 3 study

Background: Evaluation of brain beta-amyloid by positron emission tomography (PET) imaging can assist in the diagnosis of Alzheimer disease (AD) and other dementias. Methods: Open-label, nonrandomized, multicenter, phase 3 study to validate the F-18-labeled beta-amyloid tracer florbetaben by comparing in vivo PET imaging with post-mortem histopathology. Results: Brain images and tissue from 74 deceased subjects (of 216 trial participants) were analyzed. Forty-six of 47 neuritic beta-amyloid-positive cases were read as PET positive, and 24 of 27 neuritic beta-amyloid plaque-negative cases were read as PET negative (sensitivity 97.9% [95% confidence interval or CI 93.8-100%], specificity 88.9% [95% CI 77.0-100%]). In a subgroup, a regional tissue-scan matched analysis was performed. In areas known to strongly accumulate beta-amyloid plaques, sensitivity and specificity were 82% to 90%, and 86% to 95%, respectively. Conclusions: Florbetaben PET shows high sensitivity and specificity for the detection of histopathology-confirmed neuritic beta-amyloid plaques and may thus be a valuable adjunct to clinical diagnosis, particularly for the exclusion of AD. (C) 2015 The Authors. Published by Elsevier Inc. on behalf of the Alzheimer'sAssociation.