News | PET Imaging | May 17, 2018

PET Imaging Agent Could Provide Early Diagnosis of Rheumatoid Arthritis

Novel PET agent demonstrates value as inflammation biomarker before onset of clinical symptoms

PET Imaging Agent Could Provide Early Diagnosis of Rheumatoid Arthritis

Coronal 18F-FEDAC PET/CT section of a mouse with collagen-induced arthritis. (A) On day 23 and day 37, increased uptake is noted in the front and hind paws of this mouse with collagen-induced arthritis. (B) Predictive performance of day 23 18F-FEDAC uptake for the development of clinical arthritis. ROC = receiver operating characteristic; Sn = sensitivity; Sp = specificity. Credit: Seoul National University and Ewha Womans University, Seoul, South Korea

May 17, 2018 — A novel positron emission tomography (PET) tracer developed by Korean researchers can visualize joint inflammation and could provide early diagnosis of rheumatoid arthritis, a common autoimmune disease that causes chronic inflammation of joints and can lead to deformity and dysfunction. The study is reported in the featured basic science article in The Journal of Nuclear Medicine’s May issue.

Activated macrophages, white blood cells that help protect the body from harmful bacteria and infected cells, are known to play a pivotal role in rheumatoid arthritis (RA) development. Focusing on the translocator protein (TSPO), which is abundant in activated macrophages, researchers developed fluorine-18 (18F)-FEDAC, a radiolabeled ligand that targets TSPO and binds to it.

“This study is novel because it showed the value of 18F-FEDAC PET as an inflammation biomarker for early detection of rheumatoid arthritis, even before onset of clinical symptoms of joints,” explained Gi Jeong Cheon, M.D., Ph.D., of Seoul National University College of Medicine in Seoul, Korea.

For the study, 18F-FEDAC was tested in a mouse model, using both 18F-FEDAC and 18F-FDG PET imaging. Microscopic examinations of tissue were performed to evaluate macrophages and TSPO expression.

Results showed increased TSPO mRNA and protein expression in activated macrophages, and uptake of 18F-FEDAC in activated macrophages was higher than it was in non-activated cells. In addition, 18F-FEDAC uptake by arthritic joints increased early on (day 23), whereas 18F-FDG uptake did not. However, 18F-FDG uptake by arthritic joints increased at later stages (day 37) to a higher level than 18F-FEDAC uptake.

This early study demonstrates that 18F-FEDAC makes it possible to see active inflammation sites in arthritic joints by targeting TSPO expression in activated macrophages, and it suggests imaging with 18F-FEDAC could be useful when RA is suspected.

Cheon pointed out, “Early treatment can reduce the progression of joint destruction and enhance the effect of disease-modifying antirheumatic drugs or target drugs, because the burden of inflammatory reaction is smaller in the very early phase of RA.” He noted, “We observed that 18F-FEDAC uptake increased in paws of murine RA models in association with TSPO expression of activated macrophages, even before the onset of clinical symptoms of arthritis. 18F-FEDAC can help us to find which patients will actually progress to clinically significant rheumatoid arthritis and need treatment.”

Reflecting on the comparison of 18F-FEDAC PET with 18F-FDG, Cheon stated, “From our data, we found that each tracer may be useful for different information about arthritis — 18F-FEDAC for early detection of subclinical arthritis and 18F-FDG for measuring disease activity of symptomatic arthritis. These findings are expected to contribute to the improvement of personalized therapeutic outcomes by expanding the scope of molecular imaging and nuclear medicine.”

For more information: www.jnm.snmjournals.org

 

Related Content

United Imaging Announces First U.S. Clinical Installation of uExplorer Total-body PET/CT
News | PET-CT | August 15, 2019
United Imaging announced that its uExplorer total-body positron emission tomography/computed tomography (PET/CT) system...
ASRT Supports Radiopharmaceutical Reimbursement Bill
News | Radiopharmaceuticals and Tracers | August 02, 2019
The American Society of Radiologic Technologists (ASRT) announced its support for House Resolution (HR) 3772, a measure...
International Multidisciplinary Group Publishes Recommendations for Personalized HCC Treatment With Y90 TheraSphere
News | Interventional Radiology | July 31, 2019
New consensus recommendations for personalized treatment for hepatocellular carcinoma (HCC) with BTG’s TheraSphere have...
NorthStar Medical Radioisotopes Awarded $30 Million by U.S. Department of Energy
News | Radiopharmaceuticals and Tracers | July 26, 2019
NorthStar Medical Radioisotopes LLC has been awarded $15 million in a cooperative agreement with the U.S. Department of...
NorthStar Medical Radioisotopes Completes Construction on Beloit, Wis. Molybdenum-99 Processing Facility
News | Radiopharmaceuticals and Tracers | July 16, 2019
NorthStar Medical Radioisotopes LLC  announced completion of construction on its 20,000-square-foot molybdenum-99 (Mo-...
Bracco Imaging Acquires Blue Earth Diagnostics
News | Radiopharmaceuticals and Tracers | July 01, 2019
Bracco Imaging S.p.A. has signed a definitive agreement to acquire Blue Earth Diagnostics, a molecular imaging company...
DOSIsoft Receives FDA 510(k) Clearance for Planet Onco Dose Software
Technology | Information Technology | June 20, 2019
DOSIsoft announced it has received 510(k) clearance from the U.S. Food and Drug Administration (FDA) to market Planet...
United Imaging Announces First U.S. Clinical Install of uMI 550 Digital PET/CT System
News | PET-CT | June 19, 2019
United Imaging announced the first U.S. clinical installation of the uMI 550 Digital positron emission tomography/...
International Working Group Releases New Multiple Myeloma Imaging Guidelines

X-ray images such as the one on the left fail to indicate many cases of advanced bone destruction caused by multiple myeloma, says the author of new guidelines on imaging for patients with myeloma and related disorders. Image courtesy of Roswell Park Comprehensive Cancer Center.

News | Computed Tomography (CT) | June 17, 2019
An International Myeloma Working Group (IMWG) has developed the first set of new recommendations in 10 years for...
A high-fidelity 3-D tractography of the left ventricle heart muscle fibers of a mouse

Figure 1. A high-fidelity 3-D tractography of the left ventricle heart muscle fibers of a mouse from Amsterdam Ph.D. researcher Gustav Strijkers.

News | Magnetic Resonance Imaging (MRI) | June 07, 2019
The Amsterdam University Medical Center has won MR Solutions’ Image of the Year 2019 award for the best molecular...