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

Abstract

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.

Keywords: giant cell arteritis; glucocorticoids; inflammation.

Figure 1

Involvement of arteries, differentiated regarding central segments and peripheral arteries as well as glucocorticoid (GC) treatment ((A) GC-naïve patients and (B) GC-treated patients).

Figure 2

Comparison of and SUV_max as well as the (A) cumulative and (B) current dose of GC before PET/CT imaging was performed. GC, glucocorticoid; PET, positron emission tomography; SUV_max maximum standardised uptake values.

Figure 3

(A) GCA involvement of the aorta (arrow) and its branches (arrowheads), (B) GCA of the supra-aortic arteries (arrows) and (C) GCA of the aortic arch and the thoracic aorta. GCA, giant cell arteritis.

Figure 4

Differentiation of clinical symptoms regarding the affected arterial regions: (A) cranial symptoms (headache, jaw claudication, loss of vision, amaurosis fugax), (B) PMR and (C) systemic symptoms (cough, fever, night sweats, weight loss, fatigue). GCA, giant cell arteritis; n.s., not significant; PMR, polymyalgia rheumatica.