F-18 Fdg PET/CT Findings of a Patient with Takayasu Arteritis Before and After Therapy

18F-FDG PET/CT in Late Acquisition Identifies Sites of Active Disease in Treated Takayasu Arteritis

OBJECTIVE

Few studies have taken advantage of 18F-fluorodeoxyglucose positron emission tomography associated with computed tomography (18F-FDG PET/CT) to personalize patient evaluation and identify sites of more active disease in Takayasu arteritis (TA)-treated patients. This study aimed to evaluate the utility of 18F-FDG PET/CT in late acquisition in identifying sites of active disease in patients under full treatment for TA.

METHODS

In this cross-sectional study, patients under full treatment underwent whole-body 18F-FDG PET/CT. Sites of increased 18F-FDG uptake were classified by a score of 3 on the visual scale using the liver uptake as reference. A quantitative analysis was also performed by measuring the maximum standardized uptake value (SUV) of the vascular wall of affected arteries. Disease activity using the National Institutes of Health criteria was also evaluated.

RESULTS

Of the 20 patients, there were 18 female and 2 male patients, with a mean age of 43.6 (±11.58) years and a disease duration of 8.3 (±6.25) years. Thirteen participants (65%) were in inflammatory activity according to the criteria proposed by the National Institutes of Health. All patients received immunosuppressive agents, and one of them received immunobiological treatment. The highest SUV value was 6.2 in the aortic arch, and the lowest was 1.0 in the subclavian artery. The mean maximum SUV did not differ between clinically active and inactive patients. In the visual analysis, all participants had at least 1 vascular site with inflammatory activity, with an uptake ≥2 in relation to the liver. The aortic arch was the most frequently involved site.

CONCLUSIONS

This study showed that 18F-FDG PET/CT in late acquisition is an effective imaging method to assess TA activity even in fully treated patients.

Effect of Treatment on Imaging, Clinical, and Serologic Assessments of Disease Activity in Large-vessel Vasculitis

OBJECTIVE

Disease activity in large-vessel vasculitis (LVV) is traditionally assessed by clinical and serological variables rather than vascular imaging. This study determined the effect of treatment on 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) vascular activity in relation to clinical- and serologic-based assessments.

METHODS

Patients with giant cell arteritis (GCA) or Takayasu arteritis (TA) were prospectively evaluated at 6-month intervals in an observational cohort. Treatment changes were made at least 3 months before the followup visit and categorized as increased, decreased, or unchanged. Imaging (FDG-PET qualitative analysis), clinical, and serologic (erythrocyte sedimentation rate, C-reactive protein) assessments were determined at each visit and compared over interval visits.

RESULTS

Serial assessments were performed in 52 patients with LVV (GCA = 31; TA = 21) over 156 visits. Increased, decreased, or unchanged therapy was recorded for 36-, 23-, and 32-visit intervals, respectively. When treatment was increased, there was significant reduction in disease activity by imaging, clinical, and inflammatory markers (p ≤ 0.01 for each). When treatment was unchanged, all 3 assessments of disease activity remained similarly unchanged over 6-month intervals. When treatment was reduced, PET activity significantly worsened (p = 0.02) but clinical and serologic activity did not significantly change. Treatment of GCA with tocilizumab and of TA with tumor necrosis factor inhibitors resulted in significant improvement in imaging and clinical assessments of disease activity, but only rarely did the assessments both become normal.

CONCLUSION

In addition to clinical and serologic assessments, vascular imaging has potential to monitor disease activity in LVV and should be tested as an outcome measure in randomized clinical trials.

Repetitive 18F-FDG-PET/CT in patients with large-vessel giant-cell arteritis and controlled disease

OBJECTIVE

¹⁸F-FDG PET/CT can detect large-vessel involvement in giant-cell arteritis (GCA) with a good sensitivity. In patients with clinically and biologically controlled disease, we aimed to assess how vascular uptakes evolve on repetitive FDG-PET/CT.

PATIENTS AND METHODS

All included patients had to satisfy the 4 following criteria: 1) diagnosis of GCA was retained according to the criteria of the American College of Rheumatology or based on the satisfaction of 2 criteria associated with the demonstration of large-vessel involvement on FDG-PET/CT; 2) all patients had a positive PET/CT that was performed at diagnosis before treatment or within the first 10days of treatment; 3) another FDG-PET/CT was performed after at least 3months of controlled disease without any relapse; 4) patients were followed-up at least for 12months.

RESULTS

Twenty-five patients (17 [68%] women, median age: 69 [65-78]) with large-vessel inflammation on a baseline FDG-PET/CT and with repetitive imaging during the period with controlled disease were included and followed-up for 62 [25-95] months. Four repeated procedures revealed total extinction of vascular uptakes at 11.5 [8-12] months after the first FDG-PET/CT. Eight PET/CT revealed decreased numbers of vascular uptakes, and 10 procedures revealed no changes. The 3 remaining procedures indicated worsening of the numbers of vascular uptakes in the absence of relapse.

CONCLUSIONS

Our study revealed long-term persistent vascular uptake on repeated FDG-PET/CT in >80% of our GCA patients with large-vessel inflammation and clinical-biological controlled disease. Prospective studies are required to confirm these findings.

Role of inflammatory markers in Takayasu arteritis disease monitoring

Background

Takayasu arteritis (TA) is an idiopathic large-vessel vasculitis that can result in significant morbidity and mortality secondary to progressive stenosis and occlusion. Monitoring disease progression is crucial to preventing relapse, but is often complicated by the lack of clinical symptoms in the setting of active disease. Although acute phase reactants such as ESR and CRP are generally used as an indicator of inflammation and disease activity, mounting evidence suggests that these markers cannot reliably distinguish active from inactive TA.

Case presentation

We report a 24-year-old Hispanic female with a 5-year history of TA who presented with stroke-like symptoms and evidence of left MCA occlusion on imaging, despite a history of decreasing inflammatory markers. CTA revealed complete occlusion of the left common carotid artery, left subclavian, and left MCA from their origins. It also revealed a striking compensatory circulation supplying the left anterior circulation as well as the left subclavian as a response to progressive stenosis.

Conclusion

Monitoring ESR and CRP levels alone may not be a reliable method to evaluate disease progression in patients with TA, and should be taken in context with both patient’s clinical picture and the imaging. We recommend that serial imaging be performed regularly in the setting of active disease to monitor progression and allow for immediate therapy in response to evidence of disease advancement, with a relaxation of the imaging interval once the disease is presumed inactive.

Diagnosis and assessment of disease activity in takayasu arteritis: a childhood case illustrating the challenge

Takayasu Arteritis (TA) is a rare, debilitating large vessel vasculitis occurring in patients of all ages, including infants, but the disease most commonly presents in the third decade. Diagnosis is often delayed and consequently TA is associated with significant morbidity and mortality. Accurate methods of monitoring disease activity or damage are lacking and currently rely on a combination of clinical features, blood inflammatory markers, and imaging modalities. In this report we describe a case of a 14-year-old boy with childhood-onset TA who, despite extensive negative investigations, did indeed have on-going active large vessel vasculitis with fatal outcome. Postmortem analysis demonstrated more extensive and active disease than originally identified. This report illustrates and discusses the limitations of current modalities for the detection and monitoring of disease activity and damage in large vessel vasculitis. Clinicians must be aware of these limitations and challenges if we are to strive for better outcomes in TA.