18F-Florbetaben amyloid imaging PET: A Chinese study in cognitively normal controls, mild cognitive impairment and Alzheimer’s disease patients

1558 Background: Although the deposition of amyloid-β (Aβ) is considered as one of the initial of Alzheimer’s disease (AD) and Aβ imaging agents are widely used for AD diagnosis, systematic comparison between 18F-Florbetaben (FBB) and 11C-PIB (PIB) was rarely performed in cognitively normal controls (NC), mild cognitive impairment patients (MCI) and Alzheimer’s disease patients. Compared to the 20-min radioactive half-life of 11C-PIB, 18F-Florbetaben is an Aβ ligand with a long radioactive half-life of 110 min is suitable for clinical application without generating adverse effects. The aim of this study was to evaluate Aβ deposition with 18F-FBB PET imaging against 11C-PIB PET in the Chinese clinical study of NC, MCI and AD patients. Methods: We recruited 45 subjects (15 in each group of NC, MCI and mild/moderate AD) in this clinical study. All 45 subjects underwent dynamic amyloid PET imaging (Biograph 64, Siemens, USA) after intravenous injection 300 MBq of 18F-FBB. For comparison study, 17 participants, including 6 NC, 5 MCI and 6 AD patients, were also performed 11C-PIB PET imaging on separate days after intravenous injection. In image analysis, both 18F-FBB and 11C-PIB PET images were visually and quantitatively assessed. Regions of interest (ROIs) were manually defined on coregistered CT, and standardized uptake value ratio (SUVR) were calculated using the cerebellum as reference region in the cortical regions of 90-110 min 18F-FBB and 40-60 min 11C-PIB PET images, respectively. Quantitative analysis of mean cortical uptake was calculated using Global SUVR. SUVR images were visually rated as amyloid-positive or amyloid-negative. Results: 1 (7%) of the 15 NC participants, 9 (60%) of 15 MCI patients and 14 (93%) of 15 AD patients had amyloid-positive lesions on 18F-FBB PET images. In AD patients, FBB uptake was observed both in cerebral white and gray matter, and global SUVR was significantly higher than those of MCI patients (1.73±0.62 vs. 1.55±0.11, P<0.001) and NC subjects (1.73±0.62 vs. 1.13±0.43, P<0.001). We also found that 18F-FBB binds more to NC white matter than 11C-PIB. In comparison study, 1 NC participant, 5 MCI and 5 AD patients had amyloid-positive lesions on 11C-PIB PET images. The results of 18F-FBB were comparable to 11C-PIB: there was a significant linear correlation (slope=0.43, r2=0.81, P< 0.001) between FBB and PIB global SUVR values. Conclusions: Our clinical study suggests that 18F-FBB is a useful and suitable tracer for the evaluation of β-amyloid deposition in vivo. 18F-FBB PET could generate similar metabolic images to 11C-PIB PET, and global SUVR of 18F-FBB PET might be a reliable alternative in the diagnosis of AD. Keywords: Alzheimer’s disease (AD), amyloid imaging, Florbetaben (FBB), PET, amyloid beta(Aβ) al functions in early stage of the disease independent from overall amyloid load.