FDG-PET Useful to Resolve Doubts About GCA

Soussan M, Nicolas P, Schramm C, et al. Management of Large-Vessel Vasculitis With FDG-PET: A Systematic Literature Review and Meta-Analysis.Medicine. 2015;94(14)e622. doi: 10.1097/MD.0000000000000622

¹⁸F-fluorodeoxyglucose positron emission tomography (FDG-PET) has high sensitivity and specificity for diagnosing large-vessel inflammation in giant cell arteritis (GCA). This could be useful where GCA is still suspected after a negative temporal artery biopsy.

The sensitivity and specificity for Takayasu arteritis (TA) is almost as good.

This was the result of a systematic review of 21 studies with 413 patients and 299 controls. Inflammatory cells such as macrophages or granulation tissue avidly take up FDG. FDG-PET showed FDG vascular uptake in 70% of patients and 7%ofcontrols. Only vascular uptake equal to or higher than the liver uptake was significantly different between GCA or TA patients and controls.

For GCA, the sensitivity was 90% and the specificity was 98%. For TA, the sensitivity was 87% and specificity was 73%.