Parametric Binding Images of the TSPO Ligand 18F-DPA-714.
18F-labeled N,N-diethyl-2-(2-[4-(2-fluoroethoxy)phenyl]-5,7-dimethylpyrazolo[1,5-α]pyrimidine-3-yl)acetamide (DPA-714) is a radioligand for the 18-kDa translocator protein. The purpose of the present study was to identify the best method for generating quantitative parametric images of18F-DPA-714 binding.


METHODS
Ninety-minute dynamic18F-DPA-714 PET scans with full arterial sampling from 6 healthy subjects and 9 Alzheimer disease (AD) patients were used. Plasma-input-based Logan graphical analysis and spectral analysis were used to generate parametric volume of distribution (VT) images. Five versions of Ichise, reference Logan, and 2 basis function implementations (receptor parametric mapping and simplified reference tissue model 2 [SRTM2]) of SRTM, all using gray matter cerebellum as the reference region, were applied to generate nondisplaceable binding potential (BPND) images.


RESULTS
Plasma-input Logan analysis (r2= 0.99; slope, 0.88) and spectral analysis (r2= 0.99, slope, 0.93) generated estimates of VTthat correlated well with values obtained using nonlinear regression. BPNDvalues generated using SRTM2 (r2= 0.83; slope, 0.95) and reference Logan analysis (r2= 0.88; slope, 1.01) correlated well with nonlinear regression-based estimates.


CONCLUSIONS
Both Logan analysis and spectral analysis can be used to obtain quantitatively accurate VTimages of18F-DPA-714. In addition, SRTM2 and reference Logan analysis can provide accurate BPNDimages. These parametric images could be used for voxel-based comparisons.
Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands s.golla@vumc.nl.
Sandeep S V
SS
Golla
Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands.
Ronald
R
Boellaard
Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.
Vesa
V
Oikonen
Bayer HealthCare AG, Berlin, Germany; and.
Anja
A
Hoffmann
Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands.
Bart N M
BN
van Berckel
Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands.
Albert D
AD
Windhorst
Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.
Jere
J
Virta
Center for Human Drug Research, Leiden, The Netherlands.
Erik T
ET
Te Beek
Center for Human Drug Research, Leiden, The Netherlands.
Geert Jan
GJ
Groeneveld
Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.
Merja
M
Haaparanta-Solin
Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.
Pauliina
P
Luoto
Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.
Nina
N
Savisto
Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.
Olof
O
Solin
Bayer HealthCare AG, Berlin, Germany; and.
Ray
R
Valencia
Bayer HealthCare AG, Berlin, Germany; and.
Andrea
A
Thiele
Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands.
Jonas
J
Eriksson
Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands.
Robert C
RC
Schuit
Department of Radiology and Nuclear Medicine, VU University Medical Center, Amsterdam, The Netherlands.
Adriaan A
AA
Lammertsma
Turku PET Centre, University of Turku and Turku University Hospital, Turku, Finland.
Juha O
JO
Rinne
D000328:Adult; D000544:Alzheimer Disease / Q000000981:diagnostic imaging / Q000378:metabolism; D016022:Case-Control Studies; D005260:Female; D005462:Fluorine Radioisotopes; D006801:Humans; D008024:Ligands; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D011485:Protein Binding; D011720:Pyrazoles / Q000378:metabolism*; D011743:Pyrimidines / Q000378:metabolism*; D018079:Receptors, GABA / Q000378:metabolism*; D013223:Statistics as Topic
D005462:Fluorine Radioisotopes; D008024:Ligands; C530129:N,N-diethyl-2-(2-(4-(2-fluoroethoxy)phenyl)-5,7-dimethylpyrazolo(1,5-a)pyrimidin-3-yl)acetamide; D011720:Pyrazoles; D011743:Pyrimidines; D018079:Receptors, GABA; C499229:TSPO protein, human
18F-DPA-714; PET; TSPO; parametric images