PET/CT Predicts Early Arthritis Treatment Response

New imaging technique can detect treatment effectiveness in rheumatoid arthritis patients in just 4 weeks

Published on Feb. 28, 2026

Got story updates? Submit your updates here. ›

Researchers have developed a new PET/CT imaging technique that can detect treatment response in rheumatoid arthritis patients in as little as four weeks, compared to the three to six months currently required. The technique uses a targeted tracer to quantify macrophage levels, which are a key biomarker for rheumatoid arthritis disease activity. This could allow doctors to quickly identify non-responders and switch them to more effective therapies.

Why it matters

Rheumatoid arthritis can lead to permanent joint damage if not treated effectively. The new PET/CT technique provides an objective, accurate way to assess treatment response much earlier than current methods, which is crucial for ensuring patients receive the most appropriate and effective therapies to prevent long-term complications.

The details

The study involved 20 rheumatoid arthritis patients undergoing anti-tumor necrosis factor (aTNF) treatment. Researchers conducted whole-body PET/CT scans using an 11C-DPA-713 tracer to quantify macrophage levels in 44 joints at baseline and 4 weeks after starting treatment. They found that the PET/CT measurements at baseline and 4 weeks showed a significant association with clinical disease activity at 26 weeks. Adding certain clinical data to the PET/CT results also improved the ability to predict treatment outcomes.

  • The study was conducted in February 2026.
  • Patients underwent PET/CT scans at baseline and 4 weeks after starting aTNF treatment.
  • Clinical disease activity was evaluated at 26 weeks.

The players

Wouter van Binsbergen

A student at the Amsterdam University Medical Center and lead author of the study.

Rheumatoid Arthritis

A chronic inflammatory disease that can lead to permanent joint damage if not treated effectively.

Anti-Tumor Necrosis Factor (aTNF)

A successful treatment for many rheumatoid arthritis patients, but only effective in 50-70% of cases.

Got photos? Submit your photos here. ›

What they’re saying

“Macrophages (a type of white blood cell), play a crucial role in the development and continuation of rheumatoid arthritis, and are a promising biomarker for assessment and monitoring of disease activity.”

— Wouter van Binsbergen, Lead Author (The Journal of Nuclear Medicine)

“These findings show that non-invasive assessment and monitoring of macrophages using PET/CT has value to predict very early potentially already at baseline the outcome of anti-TNF treatment in rheumatoid arthritis patients.”

— Wouter van Binsbergen, Lead Author (The Journal of Nuclear Medicine)

What’s next

The researchers plan to conduct further studies to validate the use of this PET/CT imaging technique for predicting treatment response in a larger cohort of rheumatoid arthritis patients.

The takeaway

This new PET/CT imaging approach could revolutionize the treatment of rheumatoid arthritis by allowing doctors to quickly identify which patients are likely to respond to a given therapy. This would enable them to switch non-responders to more effective treatments, preventing long-term joint damage and improving patient outcomes.