Giant Cell Arteritis: Improving Use of Ultrasound Evaluation

Study Overview
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Brief Summary
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Giant cell arteritis (GCA) is an inflammatory disease causing new, unaccustomed headache in the elderly and which can lead to blindness in 20-30% of untreated cases. The study group have previously shown that ultrasound is a viable non-invasive alternative to temporal artery biopsy in diagnosing GCA. However, there is significant variation in ultrasound assessment (measuring a dark halo around the abnormal blood vessels) between sonographers in different centres, requiring a labour intensive and time consuming training programme. The study group propose to standardise the training programme, and use ultrasound and clinical evaluation to define changes occurring over time and with treatment in patients with a diagnosis of GCA made based on ultrasound changes alone. The study group will explore the use of algorithms to automate or semi-automate image interpretation.

Detailed Description
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Objectives and Project Plan: Project Purpose: The purpose of the project is to develop the technology to reliably acquire and analyse ultrasound images through the use of a training programme which are comparable to those from scanning by an expert sonographer in the diagnosis (i.e. as a diagnostic tool) and monitoring of patients with GCA following treatment (i.e. as a response indicator), and patient stratification according to initial or early scan changes to determine the most appropriate treatment (i.e. as a prognostic tool). End Point: The end point will be the production of an effective training programme which can be used to obtain reproducible accurate ultrasound images of the temporal artery which can be automatically analysed and used in real time in the management of patients with suspected or confirmed giant cell arteritis. Milestones: The project is in 3 phases. In phase 1 (0-12 months) the study group will create a bank of images for training from healthy volunteers and patients with GCA; in phase 2 (13-18 months) the study group will test the programme on sonographers assessing patients with GCA; in phase 3 (19-42 months) the study group will acquire serial images, clinical data, serum and plasma from cohorts of patients with newly diagnosed and flaring GCA so that they can analyse and develop new software algorithms. The study group can use images already acquired from a previous diagnostic study in GCA, and test the algorithms on the new cohorts..

Official Title
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Can we Use Ultrasound in the Diagnosis and Monitoring of Patients With Giant Cell Arteritis?

Conditions
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Giant Cell Arteritis

Intervention / Treatment
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* Device: Ultrasound of temporal and axillary arteries


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy volunteer or Patient with a suspected diagnosis of GCA but found not to have GCA Recent diagnosis of GCA within 1 month or Suspected flare of GCA within one month Ability to provide written informed consent Exclusion Criteria: Unable to provide written informed consent

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Healthy volunteers<br>Age and gender matched to patient groups to undergo ultrasound of temporal and axillary arteries | Device: Ultrasound of temporal and axillary arteries<br>* Each patient will have a clinical assessment and ultrasound examination of both temporal and axillary arteries<br>|
| Patients with headache<br>Patients with new headache not due to GCA to undergo ultrasound of temporal and axillary arteries | Device: Ultrasound of temporal and axillary arteries<br>* Each patient will have a clinical assessment and ultrasound examination of both temporal and axillary arteries<br>|
| Patients with GCA (new)<br>Patients with new diagnosis of GCA to undergo ultrasound of temporal and axillary arteries | Device: Ultrasound of temporal and axillary arteries<br>* Each patient will have a clinical assessment and ultrasound examination of both temporal and axillary arteries<br>|
| Patients with GCA (flare)<br>Patients with apparent flare of GCA to undergo ultrasound of temporal and axillary arteries | Device: Ultrasound of temporal and axillary arteries<br>* Each patient will have a clinical assessment and ultrasound examination of both temporal and axillary arteries<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Size of halo detected (mm) on ultrasound of temporal arteries | The study group will compare computer algorithms to analyse the halo size from video images of ultrasound scans with observer defined measures of halo size (mm) from healthy volunteers, patients with headache but not due to GCA, patients with newly diagnosed GCA and in patients with GCA who are followed serially and re-imaged over time in response to therapy. The study group will test the value of algorithms incorporating clinical and serological data together with the imaging findings to determine their added effect on the sensitivity and specificity of ultrasound for diagnosis and monitoring of GCA. Halo size varies from 0 (undetectable) to greater than 1mm. Cut-off values for abnormal values have not been formally established or published yet. | 24 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Circulating serum Vascular Endothelial Growth Factor (VEGF) levels | The study group will measure VEGF levels in serum taken from age matched controls presenting with headache, patients with newly diagnosed GCA and patients with established GCA undergoing a flare, to determine the value of VEGF in predicting diagnosis, response to therapy, flare or prognosis in GCA. | 24 months | 
| Circulating serum Pentraxin 3 levels | The study group will measure pentraxin 3 levels in serum taken from age matched controls presenting with headache, patients with newly diagnosed GCA and patients with established GCA undergoing a flare, to determine the value of pentraxin 3 in predicting diagnosis, response to therapy, flare or prognosis in GCA. | 24 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Ultrasound