Distribution patterns of arterial affection and the influence of glucocorticoids on 18F-fluorodeoxyglucose positron emission tomography/CT in patients with giant cell arteritis

Background

Giant cell arteritis (GCA) with the involvement of extracranial vessels is increasingly coming into focus. Isolated aortic involvement in the acute phase of GCA is probably more frequent than estimated because only a minority of patients show typical symptoms. ¹⁸F-fluorodeoxyglucose positron emission tomography/CT (PET/CT) is a reliable imaging tool to diagnose patients with extracranial GCA. The aim of this retrospective study was to quantify arterial involvement at the onset of a newly diagnosed GCA by PET/CT and to evaluate the influence of glucocorticoid (GC) treatment on the diagnostic performance of this imaging technique.

Methods

The study included 60 patients with GCA at the onset of a GCA. All patients had undergone a PET/CT scan. 44 patients were GC naïve and 16 patients received GC.

Results

The most affected arteries were the ascending aorta (72%), followed by the brachiocephalic trunk (62%), aortic arch (60%) and descending aorta (60%). The aorta and its branches showed an inflammatory involvement in 83.3% of patients. A singular affection of the aorta and the brachiocephalic trunk was revealed in 20% of cases. GC-naïve patients (95.5%) had more frequently affected arteries compared with GC-treated patients (50%).

Conclusion

Our study showed the frequent involvement of the thoracic aorta and brachiocephalic trunk in patients with GCA using PET/CT. Since these vascular compartments cannot be visualised by ultrasound, we advocate screening imaging of the aorta with PET/CT when GCA is suspected. Because the use of GC is associated with a marked decrease in the inflamed vascular segment in GCA, PET/CT should be performed as soon as possible.

AB1353 VESSEL AFFECTION AND THE INFLUENCE OF GLUCOCORTICOIDS ON 18F-FLUORODEOXYGLUCOSE POSITRON EMISSION TOMOGRAPHY/COMPUTED TOMOGRAPHY IN GIANT CELL ARTERITIS

Background

18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) represents one of the standard imaging modalities in the detection of giant cell arteritis (GCA). Detailed data regarding the vessel involvement in GCA are not available.

Objectives

The aim of this study was to quantify arterial vessel involvement at the onset of GCA by 18F-FDG PET/CT and to verify the influence of glucocorticoid treatment on the diagnostic performance of 18F-FDG PET/CT.

Methods

This study included 60 patients (44 women and 16 men, mean age 72.8 ± 8.8 years) at the onset of GCA. All patients received a PET/CT. 44 patients were glucocorticoid naïve. 16 patient were treated with glucocorticoid (prednisone median dose 60 mg) 3.5 ± 4.4 days before the 18F-FDG PET/CT was performed. All 18F-FDG PET/CT scans were scored regarding the active inflammation of the large arteries.

Results

The most affected arteries were the aorta ascendens (72 %), followed by truncus brachiocephalicus (62 %), acrus aortae (60 %), aorta descendens (60 %), left and right arteria sublcavia (60 % and 58 %). The aorta and their outgoing arteries presented an involvement in 39 GCA patients (89 %). A singular affection of the aorta was shown in 9 patients (20 %). glucocorticoid naïve patients (89 %) showed affected arteries more frequently than glucocorticoid treated patients (38 %).

Conclusion

The study showed that the thoracic aorta (in particular aorta ascendens) is the most involved vascular segment in GCA. The use of glucocorticoids was associated with a marked decrease of vascular inflammation. Consequently, the imaging of the thoracic aorta should be included in the diagnostic procedure of GCA. 18F-FDG PET/CT should be performed without glucocorticoid treatment, if the clinical situation allowed this proceeding.

Disclosure of Interests

Leander Malich: None declared, Falk Gühne: None declared, Tobias Hoffmann: None declared, Ansgar Malich: None declared, Peter Oelzner: None declared, Gunter Wolf: None declared, Martin Freesmeyer: None declared, Alexander Pfeil Grant/research support from: This study is a part of the Investigator Initiated study Retrospective analysis of clinical and imaging parameters to predict flair in patients with giant cell arteritis.” which is supported by Chugai Pharma Germany GmbH, Lyoner Straße 15, 60528 Frankfurth am Main.