Impact of point-spread function reconstruction on dynamic and static 18F-DOPA PET/CT quantitative parameters in glioma

Antoine Girard; Madani François; Nibras Chaboub; Pierre-Jean Le Reste; Anne Devillers; Hervé Saint-Jalmes; Florence Le Jeune; Xavier Palard-Novello

doi:10.21037/qims-21-742

Impact of point-spread function reconstruction on dynamic and static ¹⁸F-DOPA PET/CT quantitative parameters in glioma

Quant Imaging Med Surg. 2022 Feb;12(2):1397-1404. doi: 10.21037/qims-21-742.

Authors

Antoine Girard¹, Madani François², Nibras Chaboub², Pierre-Jean Le Reste³, Anne Devillers², Hervé Saint-Jalmes², Florence Le Jeune¹, Xavier Palard-Novello²

Affiliations

¹ Univ Rennes, CLCC Eugène Marquis, Noyau Gris Centraux EA 4712, Rennes, France.
² Univ Rennes, CLCC Eugène Marquis, INSERM, LTSI-UMR 1099, Rennes, France.
³ CHU Rennes, Rennes, France.

Abstract

Background: Quantification of dynamic and static parameters extracted from 3,4-dihydroxy-6-[¹⁸F]-fluoro-L-phenylalanine (¹⁸F-DOPA, FDOPA) positron emission tomography (PET)/computed tomography (CT) plays a critical role for glioma assessment. The objective of the present study was to investigate the impact of point-spread function (PSF) reconstruction on these quantitative parameters.

Methods: Fourteen patients with untreated gliomas and investigated with FDOPA PET/CT were analyzed. The distribution of the 14 cases was as follows: 6 astrocytomas-isocitrate dehydrogenase-mutant; 2 oligodendrogliomas/1p19q-codeleted-isocitrate dehydrogenase-mutant; and 6 isocitrate dehydrogenase-wild-type glioblastomas. A 0-20-min dynamic images (8×15, 2×30, 2×60, and 3×300 s post-injection) and a 0-20-min static image were reconstructed with and without PSF. Tumoral volumes-of-interest were generated on all of the PET series and the background volumes-of-interest were generated on the 0-20-min static image with and without PSF. Static parameters (SUVmax and SUVmean) of the tumoral and the background volumes-of-interest and kinetic parameters (K1 and k2) of the tumoral volumes-of-interest extracted from using full kinetic analysis were provided. PSF and non-PSF quantitative parameters values were compared.

Results: Thirty-three tumor volumes-of-interest and 14 background volumes-of-interest were analyzed. PSF images provided higher tumor SUVmax than non-PSF images for 23/33 VOIs [median SUVmax =3.0 (range, 1.4-10.2) with PSF vs. 2.7 (range, 1.4-9.1) without PSF; P<0.001] and higher tumor SUVmean for 13/33 volumes-of-interest [median SUVmean =2.0 (range, 0.8-7.6) with PSF vs. 2.0 (range, 0.8-7.4) without PSF; P=0.002]. K1 and k2 were significantly lower with PSF than without PSF [respectively median K1 =0.077 mL/ccm/min (range, 0.043-0.445 mL/ccm/min) with PSF vs. 0.101 mL/ccm/min (range, 0.055-0.578 mL/ccm/min) without PSF; P<0.001 and median k2 =0.070 min^-1 (range, 0.025-0.146 min^-1) with PSF vs. 0.081 min^-1 (range, 0.027-0.180 min^-1) without PSF; P<0.001]. Background SUVmax and SUVmean were statistically unaffected [respectively median SUVmax =1.7 (range, 1.3-2.0) with PSF vs. 1.7 (range, 1.3-1.9) without PSF; P=0.346 and median SUVmean =1.5 (range, 1.0-1.8) with PSF vs. 1.5 (range, 1.0-1.7) without PSF; P=0.371].

Conclusions: The present study confirms that PSF significantly increases tumor activity concentrations measured on PET images. PSF algorithms for quantitative PET/CT analysis should be used with caution, especially for quantification of kinetic parameters.

Keywords: 3,4-dihydroxy-6-[18F]-fluoro-L-phenylalanine (FDOPA); gliomas; kinetic; point-spread function (PSF); positron emission tomography (PET).