2009-10-20 Vesa Oikonen

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Quantification of TSPO with[¹⁸F]DPA-714

Background

DPA-714 (and previous molecule DPA-713) is a selective ligand for the translocator protein (18 kDa), TSPO, formerly known as peripheral benzodiazepine receptor (PBR).

James et al. (2008) performed [¹⁸F]DPA-714 PET studies with rats and a baboon (P. hamadryas). Studies showed rapid brain uptake, good retention, and effective displacement (James et al., 2008).

Chauveau et al. (2009) compared F-18 labeled DPA-714 to C-11 labeled DPA-713 and to the classical (but not optimal) PBR PET tracer [¹¹C]PK11195 in a rat model of acute neuroinflammation, and found that the highest binding potential (BP) and ipsilaterial-to-contralateral ratio were achieved with [¹⁸F]DPA-714. Displacement studies provided additional support for the usefulness of this tracer.

Metabolism

In rat brain, only intact [¹⁸F]DPA-714 could be detected up to 60 min after injection (Chauveau et al., 2009). One radioactive metabolite was detected in the plasma. Parent tracer fractions were 75%, 63% and 14% at 20, 40 and 60 min after injection (Chauveau et al., 2009). Similar results were obtained with [¹¹C]DPA-713 (Boutin et al., 2007).

Published analysis methods

Chauveau et al. (2009) analyzed [¹⁸F]DPA-714 rat brain studies with SRTM, using contralateral ROI as reference input curve. PET scan duration was 70 min. BP was 3.08 ± 0.67. R1 was higher (1.64 ± 0.27) than with [¹¹C]PK11195 (1.10 ± 0.06) or [¹¹C]DPA-713 (1.30 ± 0.27).

Suggested analysis method for Turku

NA.

See also

• Quantification of [¹¹C]-R-PK11195 brain PET studies

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References:

Boutin H, Chauveau F, Thominiaux C, Grégoire M-C, James ML, Trebossen R, Hantraye P, Dollé F, Tavitian B, Kassiou M. ¹¹C-DPA-713: A novel peripheral benzodiazepine recptor PET ligand for in vivo imaging of neuroinflammation. J Nucl Med. 2007; 48: 573-581.

Chauveau F, Van Camp N, Dollé F, Kuhnast B, Hinnen F, Damont A, Boutin H, James M, Kassiou M, Tavitian B. Comparative evaluation of the translocator protein radioligands ¹¹C-DPA-713, ¹⁸F-DPA-714, and ¹¹C-PK11195 in a rat model of acute neuroinflammation. J Nucl Med. 2009 (in press).

Doorduin J, Klein HC, Dierckx RA, James M, Kassiou M, de Vries EFJ. [¹¹C]-DPA-713 and [¹⁸F]-DPA-714 as new PET tracers for TSPO: a comparison with [¹¹C]-(R)-PK11195 in a rat model of Herpes Encephalitis. Mol Imaging Biol. 2009; 11: 386-398.

James ML, Fulton RR, Vercoullie DJ, Henderson DJ, Garreau L, Chalon S, Dolle F, Costa B, Guilloteau D, Kassiou M. DPA-714, a new translocator protein-specific ligand: synthesis, radiofluorination, and pharmacologic characterization. J Nucl Med. 2008; 49: 814-822.

Martín A, Boisgard R, Thézé B, Van Camp N, Kuhnast B, Damont A, Kassiou M, Dollé F, Tavitian B. Evaluation of the PBR/TSPO radioligand [¹⁸F]DPA-714 in a rat model of focal cerebral ischemia. J Cereb Blood Flow Metab. 2009 (in press).

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