[18F]flutemetamol amyloid positron emission tomography in preclinical and symptomatic Alzheimer's disease: Specific detection of advanced phases of amyloid-β pathology

Background: Amyloid positron emission tomography (PET) has become an important tool to identify amyloid-beta (A beta) pathology in Alzheimer's disease (AD) patients. Here, we determined the diagnostic value of the amyloid PET tracer [F-18]flutemetamol in relation to A beta pathology at autopsy. Methods: [F-18]flutemetamol PET was carried out in a cohort of 68 patients included in a [F-18]flutemetamol amyloid PET imaging end-of-life study (GE067-007). At autopsy, AD pathology was determined and A beta plaque pathology was classified into phases of its regional distribution (0-5). Results: [F-18]flutemetamol PET was universally positive in cases with advanced stage postmortem A beta pathology (A beta phases 4 and 5). Negative amyloid PET was universally observed in nondemented or non-AD dementia cases with initial A beta phases 1 and 2, whereas 33.3% of the phase 3 cases were positive. Conclusions: [F-18]flutemetamol amyloid PET detects primarily advanced stages of A beta pathology in preclinical and symptomatic AD cases. (C) 2015 The Authors. Published by Elsevier Inc. on behalf of the Alzheimer's Association.