April 14, 2010 - Researchers found a new amyloid imaging agent for positron emission tomography (PET) to be efficacious in assigning patients with clinically probable Alzheimer's disease (AD) or amnestic mild cognitive impairment (MCI).
The multicenter phase II trial, Primary Outcome Analysis of the Multicentre Phase II Trial of 18F-Flutemetamol, a Pittsburgh Compound B Derivative for In Vivo Beta Amyloid Imaging, focused on 18F-Flutemetamol, a Pittsburgh compound B derivative for in vivo beta amyloid imaging. Primary outcome analysis found the agent used with PET identified patients likely to have AD or amnestic MCI. Results also showed healthy controls (HC) were at a raised versus normal uptake category.
The viability of the agent, 18F-flutemetamol PET, could augment the impact of beta amyloid imaging on research and clinical practice since its use does not require an on-site cyclotron.
In the trial, which GE Healthcare supported, there were 27 patients with early-stage AD, 20 with MCI. Fifteen had HC above and 10 below 55 years. 20 of the AD and 20 of the MCI cases also underwent a 11C-PIB PET. Five central independent readers blinded to the clinical diagnosis assigned the 18F-flutemetamol scans to either raised or normal uptake categories in a binary way on the basis of visual assessment. As a primary outcome, the researchers used clinical diagnosis as SOT to calculate sensitivity and specificity of visual assessment of AD and HC scans. They also determined concordance between visual assignment and assignment based on standardized uptake value ratios in a composite cortical region (SUVRcomp).
They found the visual assessment assigned 25/27 scans from the AD group to the raised category, 1/15 scans from the elderly HC, and 9/20 scans from the MCI group. Sensitivity and specificity with clinical diagnosis as SOT (AD vs HC) was 92.6 percent and 96 percent, respectively. The correlation coefficient between 18F flutemetamol SUVRcomp and 11C-PIB SUVRcomp was 0.94.
The researchers concluded the study met their primary outcome and supports a role for 18F-flutemetamol PET as a potential biomarker for AD-related amyloidosis.
The investigators will present the results from the study on April 16 at the 62nd American Academy of Neurology in Toronto, Canada.
For more information: www.aan.com/go/am10
July 30, 2024 
