Evaluation of Ultrasound and PET/CT in the Diagnosis and Monitoring of Giant Cell Arteritis

Completed

Conditions: Vasculitis
Giant Cell Arteritis

Interventions: Diagnostic Test: Ultrasound

Registration Number: NCT03765424

Lead Sponsor: University of Aarhus

Brief Summary: The aim of this project is to prospectively evaluate the diagnostic accuracy of different imaging tools in specific giant cell arteritis disease subsets before and after treatment initiation. Diagnostic tools with high sensitivity and specificity are a prerequisite for optimal treatment of GCA patients.

Specifically, the diagnostic accuracy of ultrasound (US) as compared to 18F-FDG PET/CT in new-onset, treatment naïve large vessel(LV)-GCA patients is investigated. Furthermore, long-term follow up including US, 18F-FDG PET/CT and cross sectional imaging is performed to explore the potential of imaging as monitoring and prognostic tools.

In this observational cohort, the diagnostic accuracy of 18F-FDG PET/CT after three and ten days of glucocorticoid treatment in the subset of LV-GCA patients and the diagnostic accuracy of 18F-FDG PET/CT in cranial artery inflammation in new-onset, treatment naïve c-GCA patients as compared to a control group of patients with a previous diagnosis of malignant melanoma was also evaluated and is registered elsewhere (ClinicalTrials.gov Identifier: NCT03285945 and NCT03409913, respectively)

Detailed Description: The diagnosis of GCA is clinical and syndrome-based. Only few years ago, temporal artery biopsy (TAB) was the standard diagnostic tool to confirm diagnosis, although sensitivity is moderate\[3,4\] and its outcome seldom affects treatment management\[5\]. Today, the European League Against Rheumatism (EULAR) recommends diagnostic imaging in all patients suspected of GCA\[6\]. The imaging of choice is based on the suspected vessel involvement. In patients suspected of cranial GCA (c-GCA), vascular ultrasound (US) is the recommended first line imaging test, whereas Fluorine-18-fluorodeoxyglucose (18F-FDG) positron emissions tomography/computed tomography (PET/CT) is not recommended for the assessment of cranial arteries.

In patients suspected of large vessel involvement (LV-GCA), 18F-FDG PET/CT, US, magnetic resonance imaging (MRI) or CT can be used to confirm disease, but no specific priority of the imaging tests is given. US is an attractive first line imaging in LV-GCA suspected patients since it is increasingly used in the diagnosis of c-GCA, is readily available and cheap. 18F-FDG PET/CT is an appealing diagnostic tool in LV-GCA suspected patients, since it also evaluates malignancy and infection, differential diagnoses often considered in this disease subset. However, 18F-FDG PET/CT is often not readily available, is expensive and exposes patients to radiation. Moreover, its sensitivity seems to decrease with glucocorticoid (GC) treatment and the window of opportunity in which sensitivity is unaffected is unknown.

Relapse during glucocorticoid tapering is frequent in GCA. However, the evaluation of potential GCA disease activity relies on unspecific symptoms and inflammatory biomarkers. There is a significant overlap between symptoms of GCA disease activity and GC adverse effect and the same holds for symptoms and biomarkers of disease activity and infection, making the evaluation difficult. Accurate tools to support treatment decisions, avoid over-treatment without risk of GCA related complications are lacking.

The aim of this project is to prospectively evaluate the diagnostic accuracy of different imaging tools in specific giant cell arteritis disease subsets before and after treatment initiation. Diagnostic tools with high sensitivity and specificity are a prerequisite for optimal treatment of GCA patients.

Specifically, the diagnostic accuracy of ultrasound (US) as compared to 18F-FDG PET/CT in new-onset, treatment naïve large vessel(LV)-GCA patients is investigated. Furthermore, long-term follow up including US, 18F-FDG PET/CT and cross sectional imaging is performed to explore the potential of imaging as monitoring and prognostic tools.

In this observational cohort, the diagnostic accuracy of 18F-FDG PET/CT after three and ten days of glucocorticoid treatment in the subset of LV-GCA patients and the diagnostic accuracy of 18F-FDG PET/CT in cranial artery inflammation in new-onset, treatment naïve c-GCA patients as compared to a control group of patients with a previous diagnosis of malignant melanoma was also evaluated and is registered elsewhere (ClinicalTrials.gov Identifier: NCT03285945 and NCT03409913, respectively)

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 101

Inclusion Criteria

Age more than 50 years
C-reactive protein (CRP)>15 mg/L or erythrocyte sedimentation rate (ESR)>40 mm/h
Either
1. cranial symptoms such as new-onset headache or scalp tenderness, jaw or tongue claudication, visual disturbances
2. new-onset limb claudication
3. protracted constitutional symptoms, defined as weight loss>5 kilograms or fever>38 degrees Celcius for >3 weeks
4. Bilateral shoulder pain and morning stiffness.

Exclusion Criteria

oral glucocorticoid treatment within the past month;
subcutaneous, intramuscular, intra-articular or intravenous glucocorticoid within the past 2 months;
DMARD treatment or other immunosuppressive therapy within the past 3 months;
ongoing treatment with interleukin2;
previous diagnosis of GCA or polymyalgia rheumatica;
any disease potentially causing large vessel inflammation, that is autoimmune diseases; rheumatoid arthritis, Cogans syndrome, relapsing polychondritis, ankylosing spondylitis, systemic lupus erythematosus, Buerger's disease, Bechet's disease, inflammatory bowel disease, infections; syphilis, known active current or history of recurrent tuberculosis, hepatitis or HIV, or other large vessel disease; sarcoidosis, neurofibromatosis, congenital coarctation, Marfans syndrome, Ehlers-Danlos syndrome, retroperitoneal fibrosis.

Study Type: OBSERVATIONAL

Study Design: Not specified

Arm && Interventions

Group	Intervention	Description
controls	Ultrasound	Controls were GCA suspected patients in whom GCA diagnosis was dismissed.
GCA cases	Ultrasound	GCA cases were patients with a clinical diagnosis of GCA based on a rheumatologists evaluation of history taking, physical examination, laboratory screening and initial PET report (reporting potential large vessel inflammation but not considering cranial artery inflammation). GCA was considered large vessel (LV) and/or cranial (c) GCA cases: LV-GCA cases were patients with a clinical diagnosis of GCA and verified LV inflammation by 18F-FDG PET/CT with or without concomitant c-GCA. C-GCA cases, for the exploratory analysis of the performance of US and PET in c-GCA, were patients with a clinical diagnosis of GCA fulfilling the 1990 American College of Rheumatology (ACR) criteria, with or without concomitant LV-GCA.

Primary Outcome Measures

Name	Time	Method
Diagnostic accuracy of large vessel ultrasound with PET/CT as reference	Time of diagnosis/pre-treatment	Large vessel ultrasound for LV-GCA diagnosis is considered positive in the presence of a halo in carotid and/or axillary arteries.

Secondary Outcome Measures

Name	Time	Method
Composite halo score for monitoring disease activity (week 8, 24 and 15 months)	week 8, 24 and 15 months after initiated treatment	Composite halo score
Intima media thickness for monitoring disease activity (week 8, 24 and 15 months)	week 8, 24 and 15 months after initiated treatment	Maximum intima media thickness (IMT) measurement on US
Large vessel intima-media thickness (IMT) cut off for LV-GCA diagnosis with PET/CT as reference	Time of diagnosis/pre-treatment	IMT measurement performed on the distal vessel wall in carotid and axillary arteries
PETVAS for GCA prognosis (baseline)	4-5 years after diagnosis	PETVAS score (summarising graded (1-4) FDG uptake in arterial vessel segments)
Diagnostic accuracy vascular ultrasound (overall)	Time of diagnosis/pre-treatment	Vascular ultrasound for GCA diagnosis is considered positive in the presence of a halo in temporal, carotid and/or axillary arteries.
Halo sign for monitoring disease activity (week 8, 24 and 15 months)	week 8, 24 and 15 months after initiated treatment	Presence or absence of halos on US
Diagnostic accuracy of vascular ultrasound after treatment (day 3, 10 and week 8)	3 days, 10 days and 8 weeks after initiated treatment	Vascular ultrasound for GCA diagnosis is considered positive in the presence of a halo in temporal, carotid and/or axillary arteries.
Diagnostic accuracy of PET/CT of cranial arteries for c-GCA diagnosis (reference: American College of Rheumatology 1990 criteria)	Time of diagnosis/pre-treatment	cranial artery (vertebral, maxillary and temporal) FDG uptake above surrounding tissue FDG uptake is considered consistent with vasculitis
Temporal artery biopsy	Time of diagnosis	Temporal artery biopsy considered positive in the presence of an inflammatory infiltrate in any vessel wall layer
PETVAS for monitoring disease activity (15 months)	15 months after treatment is initiated	Composite PET scores (e.g.PETVAS)
FDG burden for GCA prognosis (baseline)	4-5 years after diagnosis	Composite scores of arterial FDG uptake (summarising FDG uptake in voxels of interest)
Semiquantitative FDG measure for monitoring disease activity (15 months)	15 months after treatment is initiated	Maximum semiquantitative FDG measures
FDG burden for monitoring disease activity (15 months)	15 months after treatment is initiated	Composite scores of FDG inflammatory burden (summarising FDG uptake in voxels of interest)
Semiquantitative FDG measure for GCA prognosis (baseline)	4-5 years after diagnosis	Maximum semiquantitative FDG measures
Aortic diameter 4-5 years after diagnosis	4-5 years after diagnosis	Aortic diameter on cross sectional imaging
Vessel wall thickening 4-5 years after diagnosis	4-5 years after diagnosis	Vessel wall thickening

Evaluation of Ultrasound and PET/CT in the Diagnosis and Monitoring of Giant Cell Arteritis

Recruitment & Eligibility

Study & Design

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