Use of PET/MR Imaging in Chronic Pain

Study Overview
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Brief Summary
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The investigators are studying the ability of PET/MR imaging (using the PET tracer [18F]FDG) to objectively identify and characterize pain generators in patients suffering from chronic pain.

Detailed Description
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The diagnosis and management of chronic and neuropathic pain syndromes remains a major clinical challenge, and this failure is partly attributed to our inability to identify the hypersensitive and inflammatory changes in the pain-sensing part of our nervous system that is thought to contribute to these syndromes. The lack of a specific, objective diagnostic test for chronic and neuropathic pain syndromes can result in a delay of diagnosis and suboptimal management decisions. This delay in diagnosis is quite unfortunate since the early diagnosis and treatment of a disease is attributed to the highest probability of remission in certain chronic pain syndromes. Additionally, identifying the correct source of pain is of paramount importance since the clinical course and therapeutic interventions are different depending on cause. Evidence in the literature points strongly toward an active inflammatory component in chronic pain. For example, soft tissue and bony inflammation is known to be an important pathophysiological mechanism for the symptoms of certain neuropathic pain syndromes. Similarly, individuals suffering from chronic sciatica or radiculopathy may suffer from a combination of inflammation and compression of lumbar or cervical spinal nerves. It is also established that inflammatory lesions have increased metabolism and energy requirements and, therefore, are more glucose-avid than normal tissues, showing increased uptake of radiolabeled glucose analogs, such as [18F]fluorodeoxyglucose ([18F]FDG). Correspondingly, [18F]FDG positron emission tomography-magnetic resonance imaging (PET/MRI) represent leading FDA-approved clinical imaging modalities to longitudinally study metabolic changes in the nervous system and non-neural tissues (e.g., muscle, blood vessels, joints, bone, scar tissue, etc.) in patients with chronic pain conditions. One of the goals of the study is to determine whether [18F]FDG PET/MRI can identify sources of inflammation with greater sensitivity, accuracy and objectivity than current diagnostic methods.

Official Title
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Use of [18F]FDG PET/MRI in the Diagnosis of Pain Generators and/or Sites of Inflammation and to Monitor Treatment Effects in Patients With Chronic Pain

Conditions
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Chronic Pain

Intervention / Treatment
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* Drug: [18F]FDG
* Device: PET/MRI


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age 18 years or older. Chronic pain lasting greater than 2 months. For example: Low back pain, sciatica, complex regional pain syndrome, peripheral nerve injury, fibromyalgia, neuropathy, osteoarthritis, cancer pain, persistent post-operative pain, and migraine. Provides informed consent On a typical day, pain level of at least 4/10 on a 0-10 Comparative Pain Scale Covid Vaccination status: Vaccinated or unvaccinated subjects who received a negative test result from the Covid test within 72 hours of the scan. Exclusion Criteria: MRI-incompatible Diabetes Pregnant or nursing Non-English speaker Claustrophobic

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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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Interventional Model Description: Participants will be recruited based on established criteria for chronic pain. For the PET/MRI scan, the participants will be injected with 10 mCi±1 mCi of [18F]FTC-146 via the antecubital vein in a bolus injection. PET and MRI scans will be acquired simultaneously using a hybrid PET/MRI scanner. Following the scan, participants will be contacted to check for adverse drug events, and any events will be recorded in the case report. The biodistribution of radiotracer will be analyzed using regions of interest (ROI) marked on anatomical structures on magnetic resonance images and quantifying the signal in PET images within the same ROIs. Pharmacokinetic information will be derived using mathematical modeling. Data from chronic pain patients will be compared to historical data from asymptomatic controls.
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Single Arm<br>[18F]FDG PET/MRI | Drug: [18F]FDG<br>* 10 mCi of [18F]FDG via the antecubital vein in a bolus injection<br>* Other names: [18F]Fluorodeoxyglucose;Device: PET/MRI<br>* PET/MRI hybrid scanner used as diagnostic device<br>* Other names: Positron emission tomography/magnetic resonance imaging;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| [18F]FDG PET/MRI as a spatial biomarker for chronic pain | Identification of structures with increased [18F]FDG uptake (SUVmax) corresponding to pain. | 5 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| [18F]FDG Biodistribution in Healthy Subjects | We will use PET/MRI to establish the normal range of [18F]FDG uptake. (SUVmax) in various anatomic structures, such as the spinal cord, peripheral nerves, dorsal root ganglia, muscle, bones, joints, blood vessels, of asymptomatic subjects. | 5 years | 
| 36 point Study Short-Form Health Survey | Patient-reported state of health. | 5 years | 
| Oswestry Disability Index | Measure of disability, quality of life. | 5 years | 
| Visual Analog Scale | A visual, semi-quantitative method for patient-derived self-assessment of pain intensity. | 5 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Positron emission tomography, Magnetic Resonance Imaging, PET/MRI, Fluorodeoxyglucose, FDG, Pain, Chronic Pain, Neuropathic Pain, Inflammatory Pain, Nociceptive Pain