Imaging of ανβ3 integrin expression in rheumatoid arthritis with [68Ga]Ga-NODAGA-RGDyk PET/CT in comparison to [18F]FDG PET/CT

Abstract [68Ga]Ga-NODAGA-RGDyk PET/CT and [18F]FDG PET/CT were performed in a 65-year-old woman during the work-up of a squamous cell carcinoma of the tongue within a clinical study protocol. Images revealed both tracers’ uptake in the primary tumor and cervical lymph nodes, but also bilaterally in the shoulders, elbows, wrists, metacarpophalangeal, interphalangeal, and hip joints. The patient had been diagnosed with rheumatoid arthritis 8 years prior to the examination. Images showed a significantly higher [18F]FDG than [68Ga]Ga-NODAGA-RGDyk uptake in primary tumor and cervical lymph nodes. However, the patient with moderately active rheumatoid arthritis had similar levels of [68Ga]Ga-NODAGA-RGDyk and [18F]FDG uptake in the involved joints, but with no [68Ga]Ga-NODAGA-RGDyk uptake in the surrounding muscles, unlike with [18F]FDG. Our case suggests that [68Ga]Ga-NODAGA-RGDyk PET/CT allows imaging of integrins expression in rheumatoid arthritis, including integrins expressed in synovial angiogenesis, with potentially a better signal-to-noise ratio than on [18F]FDG PET/CT.