AUTHOR=Amat Julie , Chanchou Marion , Olagne Louis , Descamps Lucie , Flaus Anthime , Bouvet Clément , Barres Bertrand , Valla Clemence , Molnar Ioana , Cougoul Arnaud , Mathieu Sylvain , Aumaitre Olivier , Soubrier Martin , Kelly Antony , Merlin Charles , Cachin Florent 

TITLE=Utility of 18F-Fluorodeoxyglucose Positron Emission Tomography in Inflammatory Rheumatism, Particularly Polymyalgia Rheumatica: A Retrospective Study of 222 PET/CT

JOURNAL=Frontiers in Medicine

VOLUME=7

YEAR=2020

URL=https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2020.00394

DOI=10.3389/fmed.2020.00394

ISSN=2296-858X

ABSTRACT=<p><bold>Purpose:</bold> The objective of this study was to evaluate periarticular FDG uptake scores from <sup>18</sup>F-FDG-PET/CT to identify polymyalgia rheumatica (PMR) within a population presenting rheumatic diseases.</p><p><bold>Methods:</bold> A French retrospective study from 2011 to 2015 was conducted. Patients who underwent <sup>18</sup>F-FDG-PET/CT for diagnosis or follow-up of a rheumatism or an unexplained biological inflammatory syndrome were included. Clinical data and final diagnosis were reviewed. Seventeen periarticular sites were sorted by a visual reading enabling us to calculate two scores: mean FDG visual uptake score, number of sites with significant uptake same as that or higher than liver uptake intensity and by a semi-quantitative analysis using mean maximum standardized uptake value (SUVmax). Optimal cutoffs of visual score and SUVmax to diagnose PMR were determined using receiver operating characteristics curves.</p><p><bold>Results:</bold> Among 222 <sup>18</sup>F-FDG PET/CT selected for 215 patients, 161 <sup>18</sup>F-FDG PET/CT were performed in patients who presented inflammatory rheumatism as a final diagnosis (of whom 57 PMR). The presence of at least three sites with significant uptake identified PMR with a sensitivity of 86% and a specificity of 85.5% (AUC 0.872, 95% CI [0.81–0.93]). The mean FDG visual score cutoff to diagnose a PMR was 0.765 with a sensitivity of 82.5% and a specificity of 75.8% (AUC 0.854; 95% CI [0.80–0.91]). The mean SUVmax cutoff to diagnose PMR was 2.168 with a sensitivity of 77.2% and a specificity of 77.6% (AUC 0.842; 95% CI [0.79–0.89]).</p><p><bold>Conclusions:</bold> This study suggests that <sup>18</sup>F-FDG PET/CT had good performances to identify PMR within a population presenting rheumatic diseases.</p>