Three days of high-dose glucocorticoid treatment attenuates large-vessel 18F-FDG uptake in large-vessel giant cell arteritis but with a limited impact on diagnostic accuracy

Abstract

Within 3 days of high-dose glucocorticoid treatment, FDG PET/CT can diagnose LV-GCA with high sensitivity. This window of opportunity ensures that prompt glucocorticoid treatment can be initiated to avoid debilitating GCA complications with a limited effect on diagnostic accuracy. After 10 days of treatment, FDG PET/CT sensitivity decreases significantly.

FDG PET imaging in large vessel vasculitis: Stuck at the first hurdle?

“…Limited data have shown FDG uptake can drop significantly from 3‐12 days to 3 months after commencing glucocorticoid treatment, but no further decrease is seen at 6 months post‐treatment . There is no consensus on the timing, interpretation criteria for treatment response, and the clinically relevant cutoffs to differentiate vessel wall remodeling from active vasculitis, and to predict treatment outcomes.…”

Imaging for Diagnosis, Monitoring, and Outcome Prediction of Large Vessel Vasculitides

“…Typical halo sign of the common superficial temporal artery, transverse scan, in a patient with newly diagnosed GCA considerably decreases. In patients with initially positive PET-CT, only 36% had positive findings after 10 days [20]. PET-CT is however expensive, and radiation exposition is high.…”

“…Soussan M et al [54] performed a meta-analysis of studies published between January 2000 to December 2013 (21 studies, 413 patients, 299 controls) and retained a sensitivity and specificity of 87% and 73%, respectively, for discriminating active from inactive TAK. In a recently published meta-analysis on imaging modalities for the diagnosis and disease activity assessment of TAK, pooled sensitivity of FDG-PET for disease activity was 81% (95% CI, 69-89%) and pooled specificity 74% (95% CI, 55-86%) [20]. Heterogeneity of PET/CT results could be explained by varying definitions of abnormal thresholds, patient characteristics, and standards for determining disease activity, as there is no gold standard for disease activity.…”

“…A retrospective study by Spira D et al [75] suggested that contrast-enhanced MRA may be useful for monitoring disease activity in primary LVV with biological therapies, as the wall thickness significantly decreased at follow-up. Yet another study showed that MRI reveals vessel wall edema also in patients who were considered to be in clinical remission, suggesting that edema does not correlate with disease activity [20]. A more recent study assessing 20 patients with TAK prospectively found a statistically significant correlation between MRI features, including wall thickening and enhancement, suggesting active disease, as well as the Indian Takayasu activity score (ITAS) [76].…”

Fallserie: PET-CT bei entzündlichen Gefäßerkrankungen

“…Die Sensitivität der PET/CT ist bei untherapierter Erkrankung am höchsten und nimmt nach Einleiten einer antiinflammatorischen Therapie kontinuierlich ab. Aktuelle Studien legen nahe, dass bis zu 3 Tage nach Einleiten der Therapie eine ausreichende Sensitivität der PET/CT gegeben ist [8]. Metaanalysen deuten ferner darauf hin, dass die Empfindlichkeit der PET/CT bei Riesenzellarteriitis und Takayasu-Arteriitis vergleichbar ist.…”