Quantification of [F-18]DPA-714 binding in the human brain: initial studies in healthy controls and Alzheimer's disease patients
: Golla SSV, Boellaard R, Oikonen V, Hoffmann A, van Berckel BNM, Windhorst AD, Virta J, Haaparanta-Solin M, Luoto P, Savisto N, Solin O, Valencia R, Thiele A, Eriksson J, Schuit RC, Lammertsma AA, Rinne JO
Publisher: NATURE PUBLISHING GROUP
: 2015
: Journal of Cerebral Blood Flow and Metabolism
: JOURNAL OF CEREBRAL BLOOD FLOW AND METABOLISM
: J CEREBR BLOOD F MET
: 35
: 5
: 766
: 772
: 7
: 0271-678X
: 1559-7016
DOI: https://doi.org/10.1038/jcbfm.2014.261
Fluorine-18 labelled N, N-diethyl-2-(2-[4-(2-fluoroethoxy)phenyl]-5,7-dimethylpyrazolo[1,5-a]pyrimidine-3-yl) acetamide ([F-18] DPA-714) binds to the 18-kDa translocator protein (TSPO) with high affinity. The aim of this initial methodological study was to develop a plasma input tracer kinetic model for quantification of [F-18] DPA-714 binding in healthy subjects and Alzheimer's disease (AD) patients, and to provide a preliminary assessment whether there is a disease-related signal. Ten AD patients and six healthy subjects underwent a dynamic positron emission tomography (PET) study along with arterial sampling and a scan protocol of 150 minutes after administration of 250 +/- 10 MBq [F-18] DPA-714. The model that provided the best fits to tissue time activity curves (TACs) was selected based on Akaike Information Criterion and F-test. The reversible two tissue compartment plasma input model with blood volume parameter was the preferred model for quantification of [F-18] DPA-714 kinetics, irrespective of scan duration, volume of interest, and underlying volume of distribution (V-T). Simplified reference tissue model (SRTM)-derived binding potential (BPND) using cerebellar gray matter as reference tissue correlated well with plasma input-based distribution volume ratio (DVR). These data suggest that [F-18] DPA-714 cannot be used for separating individual AD patients from heathy subjects, but further studies including TSPO binding status are needed to substantiate these findings.