FDG PET/MR Imaging of Peripheral Pain Generators

FDG PET/MR Imaging of Peripheral Pain Generators in Persistent Post-Surgical Pain (PPSP)

The purpose of this research is to determine if a PET/MRI scan using FDG can accurately identify the source of chronic pain. Identifying the source of pain may help doctors treat chronic pain more effectively. Approximately 128 participants will be enrolled and can expect to be on study for up to 12 months.

Study Overview

• Status: Recruiting
• Conditions: Pain; Nociceptive Pain
• Intervention / Treatment: Drug: FDG radiotracer; Device: PET/MRI; Device: PET/CT imaging

Detailed Description

The investigators aim to precisely localize sites of increased inflammation and potentially pain generation and improve understanding of nociception and inflammation using a unique, hybrid PET/MRI approach in conjunction with intravenously, administered fluorodeoxyglucose (FDG), which has been shown with PET imaging to be an sensitive surrogate marker of inflammation.

The Primary Objective of this pilot prospective, observational research is to determine whether this approach, which combines PET/MRI and an FDA-approved radiotracer, 18F-Fluorodeoxyglucose (FDG), can accurately localize the sites of painful inflammation in individuals with persistent pain.

• Determine if increased FDG uptake on PET as measured by standard uptake value (SUV) or target-to-background (TTB) measurements is increased in area of pain symptoms when compared to same corresponding areas in healthy, asymptomatic volunteers.
• Determine whether amount of FDG uptake as measured on PET is able to localize to abnormalities when compared to MR imaging (T2 signal intensity, morphologic aberrations)

Secondary Objectives:

• Verify that the standard administered adult dose of FDG (0.14 mCi/kg/patient) used currently in the clinics can also be used to detect peripheral pain generators.
• Verify that FDG uptake in asymptomatic, healthy controls will be significantly less than their chronic pain cohorts at the same anatomic location.
• Determine whether longitudinal FDG PET/MR imaging findings in individual patients directly correlate with symptoms as they evolve over time in joint arthroplasty subjects with PPSP.
• Determine if FDG PET/MR imaging findings spatially differ between different pain types.

• Study Type: Observational
• Enrollment (Estimated): 128

Contacts and Locations

• Study Contact: Name: Radiology Studies; Phone Number: 608-282-8349; Email: Radstudy@uwhealth.org

Study Locations

• United States
  • Wisconsin
    • Madison, Wisconsin, United States, 53792
      • Recruiting
      • UW School of Medicine and Public Health

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Non-Probability Sample

Study Population

Participants with persistent post-surgical pain and asymptomatic individuals who have undergone joint arthroplasty (hip or knee) or joint arthroscopy (hip or knee).

Description

Inclusion Criteria: Persistent Post-Surgical Pain Patients

• 18-85 years old
• Presents with persistent pain with pain score of ≥4 on Numerical Rating Scale [0:10] for at least 6 months following joint arthroplasty or arthroscopy.
• Able and willing to provide informed consent
• Willing and able to undergo PET/MRI (arthroplasty and arthroscopy participants) and PET/CT (arthroplasty participants only)

Inclusion Criteria: Asymptomatic controls

• 18-85 years old
• Asymptomatic (pain score of ≤2 on the NRS) for at least 6 months following joint arthroplasty or arthroscopy.
• Able and willing to provide informed consent
• Willing and able to undergo PET/MRI

Exclusion Criteria:

• Inability to understand and communicate with the investigators to complete the study-related questionnaires.
• Any co-morbidity which results in severe systemic disease limiting function as defined by the American Society of Anesthesiology (ASA) physical status classification > 3, such as the presence of current or past (6 months) pulmonary, hepatic, renal disease, arthritis, hematopoietic, and neurological diseases not related to chronic pain.
• Pregnant or breastfeeding. (Individuals with childbearing potential will be asked to verbally confirm they are not pregnant. If they cannot confirm, they will have a urine pregnancy test either at the imaging study visit or within 7 days prior to the imaging study visit.)
• Subject with contraindication(s) to or inability to undergo PET/MRI
• Current diagnosis of malignancy of any kind. Participants in remission for at least two years and not undergoing any treatment may be considered per investigator discretion
• Current enrollment in a scientific interventional or treatment study.
• Subject unable or unwilling to provide informed consent

Study Plan

How is the study designed?

Number of groups / cohorts

4

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Open Surgical Procedure (Arthroplasty); PPSP subjects who have undergone hip (or knee) joint arthroplasty (i.e., open surgical procedure for joint replacement).; 6 month post-op scans; 12 month post-op scans; 18 month post-op scans	Drug: FDG radiotracer; Fludeoxyglucose F 18 Injection is a positron emitting radiopharmaceutical containing no-carrier added radioactive 2-deoxy-2-[18F]fluoro-D-g1ucose, which is used for diagnostic purposes in conjunction with Positron Emission Tomography (PET). It is administered by intravenous injection. Dosage planned 0.14 mCi/kg/patient.; Other Names: 18F-Fluorodeoxyglucose; fluorodeoxyglucose; Device: PET/MRI; positron emission tomography and magnetic resonance imaging; Device: PET/CT imaging; positron emission tomography and computed tomography imaging
Less Invasive Procedure (Arthroscopy); PPSP subjects who have undergone hip (or knee) arthroscopy (i.e., less invasive joint surgical procedure involving scopes and lower profile surgical tools) - 6 month post-op scans	Drug: FDG radiotracer; Fludeoxyglucose F 18 Injection is a positron emitting radiopharmaceutical containing no-carrier added radioactive 2-deoxy-2-[18F]fluoro-D-g1ucose, which is used for diagnostic purposes in conjunction with Positron Emission Tomography (PET). It is administered by intravenous injection. Dosage planned 0.14 mCi/kg/patient.; Other Names: 18F-Fluorodeoxyglucose; fluorodeoxyglucose; Device: PET/MRI; positron emission tomography and magnetic resonance imaging; Device: PET/CT imaging; positron emission tomography and computed tomography imaging
Asymptomatic: Had Total Joint Replacement (Arthroplasty); Asymptomatic subjects who have undergone total hip or total knee arthroplasty. - single scan during one study visit (up to 3.5 hours)	Drug: FDG radiotracer; Fludeoxyglucose F 18 Injection is a positron emitting radiopharmaceutical containing no-carrier added radioactive 2-deoxy-2-[18F]fluoro-D-g1ucose, which is used for diagnostic purposes in conjunction with Positron Emission Tomography (PET). It is administered by intravenous injection. Dosage planned 0.14 mCi/kg/patient.; Other Names: 18F-Fluorodeoxyglucose; fluorodeoxyglucose; Device: PET/MRI; positron emission tomography and magnetic resonance imaging; Device: PET/CT imaging; positron emission tomography and computed tomography imaging
Asymptomatic: Less Invasive Procedure (Arthroscopy); Asymptomatic subjects who have undergone hip or knee arthroscopy. - single scan during one study visit (up to 3.5 hours)	Drug: FDG radiotracer; Fludeoxyglucose F 18 Injection is a positron emitting radiopharmaceutical containing no-carrier added radioactive 2-deoxy-2-[18F]fluoro-D-g1ucose, which is used for diagnostic purposes in conjunction with Positron Emission Tomography (PET). It is administered by intravenous injection. Dosage planned 0.14 mCi/kg/patient.; Other Names: 18F-Fluorodeoxyglucose; fluorodeoxyglucose; Device: PET/MRI; positron emission tomography and magnetic resonance imaging; Device: PET/CT imaging; positron emission tomography and computed tomography imaging

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Change in SUVmax (chronic pain)	baseline (6 months post-op), 12 months post-op, 18 months post-op
SUVmax (chronic pain vs healthy)	baseline
Location of Pain Compared to Target-to-Background (TTB) or SUVmax	baseline

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Number of Participants Where Standard FDG dose was sufficient to detect region of pain (symptomatic groups)	The standard administered adult dose of FDG currently used in clinics is 0.14 mCi/kg/patient.	baseline
Variation of the maximum ratio of SUV (SUVRmax) in asymptomatic controls vs symptomatic		baseline
Variation of the maximum ratio of SUV (SUVRmax) in symptomatic participants		baseline (6 months post-op), 12 months post-op, 18 months post-op
Radiology Review Scores	Radiologists will evaluate MRI and CT images from each exam, and assign 1 point to any abnormality detected in the following compartments: prosthesis itself, bone, joint space, joint capsule, muscle, subcutaneous fat, and skin, for a total of 7 possible points. Differences in scoring from MRI vs CT images will be further investigated with a t-test.	up to 18 months post-op
Change in Pain Scores (chronic pain)	Pain will be evaluated on a scale of 0 (no pain) to 10 (worse possible pain).	baseline (6 months post-op), 12 months post-op, 18 months post-op

Collaborators and Investigators

• Sponsor: University of Wisconsin, Madison
• Collaborators: National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS); Arthroscopy Association of North America (AANA)
• Investigators: Principal Investigator: Sandip Biswal, MD, University of Wisconsin, Madison

Study record dates

Study Major Dates

• Study Start (Actual): November 19, 2024
• Primary Completion (Estimated): June 1, 2027
• Study Completion (Estimated): June 1, 2027

Study Registration Dates

• First Submitted: December 4, 2023
• First Submitted That Met QC Criteria: December 4, 2023
• First Posted (Actual): December 15, 2023

Study Record Updates

• Last Update Posted (Estimated): September 25, 2025
• Last Update Submitted That Met QC Criteria: September 24, 2025
• Last Verified: September 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neurologic Manifestations; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Pain; Nociceptive Pain; Carbohydrates; Deoxyglucose; Deoxy Sugars; Fluorodeoxyglucose F18
• Other Study ID Numbers: 2023-0884; SMPH/RADIOLOGY/RADIOLOGY (Other Identifier: UW Madison); R01AR077706 (U.S. NIH Grant/Contract); Protocol Version 11/1/2024 (Other Identifier: UW Madison)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: No