Quantitative analysis and parametric mapping of [18F]AlF-NOTA-PRGD2, [18F]FPPRGD2 and [68Ga]Ga-NOTA-PRGD2 using graphical method

Thursday, October 11, 2012 — Poster Session III
10:00 a.m. – Noon	Natcher Conference Center, Building 45	NIBIB	IMAG-10

Authors

• N Guo
• L Lang
• G Niu
• D.O. Kiesewetter
• Q Xie
• X Chen

Abstract

With favorable pharmacokinetics and binding affinity, 18F-labeled dimeric cyclic RGDyK peptide ([18F]FPPRGD2) has been intensively used as a PET imaging probe for tumor targeting. Recently, the kit formulation method using an F-18 fluoride-aluminum complex labeled RGD tracer ([18F]AlF-NOTA-PRGD2) provides a strategy for simplifying the labeling procedure to facilitate clinical translation. The purpose of this study was to quantitatively compare the pharmacokinetics and kinetic parameters of [18F]AlF-NOTA-PRGD2, [18F]FPPRGD2 and [68Ga]Ga-NOTA-PRGD2. U87MG tumor-bearing mice underwent 60-min dynamic PET scans and the time-activity curves in main organs were obtained. Kinetic parameters (Bp and VD) were calculated by Logan graphical analysis. Parametric maps were generated by voxel-level modeling. All three compounds showed high binding potential (Bp) in tumor targeting. [18F]AlF-NOTA-PRGD2 showed comparable Bp value (2.59 ± 0.27) with those of [18F]FPPRGD2 (2.24 ± 0.026) and [68Ga]Ga-NOTA-PRGD2 (2.27 ± 0.24) (p > 0.05). Little difference was found in volume of distribution (VD) among these three RGD tracers in the tumor, liver and muscle. Consequently, despite the apparent difference in tumor uptake and clearance pattern, the actual specific binding part extrapolated from the kinetic modeling appears to be comparable for all three RGD tracers and the results are more comparable than static image analysis.

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