Association of ¹⁸F‐Fluorodeoxyglucose–Positron Emission Tomography Activity With Angiographic Progression of Disease in Large Vessel Vasculitis

Abstract

Objective To assess whether vascular activity seen on 18F‐fluorodeoxyglucose–positron emission tomography (FDG‐PET) scan is associated with angiographic change in large vessel vasculitis (LVV). Methods Patients with LVV were recruited into a prospective cohort. All patients underwent magnetic resonance angiography or computed tomography angiography and FDG‐PET imaging. Follow‐up imaging using the same imaging modalities was obtained ≥6 months later per a standardized imaging protocol. Arterial damage, defined as stenosis, occlusion, or aneurysm, and corresponding FDG uptake were evaluated in 17 arterial territories. On follow‐up, development of new lesions was recorded, and existing lesions were characterized as improved, worsened, or unchanged. Results A total of 1,091 arterial territories from 70 patients with LVV (38 patients with Takayasu arteritis, 32 patients with giant cell arteritis) were evaluated. Over a median 1.6 years of follow‐up, new lesions developed only in 8 arterial territories in 5 patients with Takayasu arteritis. Arterial lesions improved in 16 territories and worsened in 6 territories. Most arterial territories that did not have vascular activity on FDG‐PET scan at baseline had no angiographic change over the follow‐up period (787 [99%] of 793). Few territories with baseline FDG‐PET activity had angiographic change over time (24 [8%] of 298), but of the territories that developed angiographic change, 80% had FDG‐PET activity at baseline. Within the same patient, an arterial territory with baseline FDG‐PET activity had significantly increased risk for angiographic change compared to a paired arterial territory without FDG‐PET activity (odds ratio 19.49 [95% confidence interval 2.44–156.02]; P < 0.01). Concomitant edema and wall thickening further increased risk for angiographic change. Conclusion Development of angiographic change was infrequent in this cohort of patients with LVV. A lack of baseline FDG‐PET activity was strongly associated with stable angiographic disease. In cases of angiographic progression, change was preceded by the presence of FDG‐PET activity.

EULAR recommendations for the use of imaging in large vessel vasculitis in clinical practice: 2023 update

“…The key modification of this recommendation is the incorporation of the concept that vascular damage mainly occurs at sites of preceding vascular inflammation 3. This suggestion is based on the results of one study of 32 GCA and 28 TAK patients, reporting that 80% of territories subsequently developing angiographic changes (stenosis or aneurysms) during follow-up displayed a significant FDG-uptake at baseline 80. On the other hand, 92% of territories with baseline FDG-PET activity did not yield angiographic changes over time.…”

Imaging in diagnosis, monitoring and outcome prediction of large vessel vasculitis: a systematic literature review and meta-analysis informing the 2023 update of the EULAR recommendations

“…Five prospective studies providing information on the role of ultrasound in GCA patients 34 42 43 and FDG-PET in GCA 40 and in both GCA and TAK patients 44 for outcome prediction were included. No data were retrieved for the remaining imaging techniques.…”

“… 40 Another study with low RoB and a mixed population of both GCA and TAK patients revealed that territories with abnormal FDG uptake at baseline were at a higher risk of developing subsequent angiographic changes (OR 19.5, 95% CI 2.44 to 156). 44 …”

Treat-to-target recommendations in giant cell arteritis and polymyalgia rheumatica

“…While the role of imaging as an outcome variable or component of remission is still unclear, there is the increasing evidence that, at least in GCA, imaging-determined signs of activity might have an impact on future relapses and vascular damage. [66][67][68] The present statement, however, should not be understood as a recommendation to reach imaging remission and/or negative acute phase reactants at all costs, rather the achievement of the target should…”