Immuno-PET and Immuno-SPECT of Rheumatoid Arthritis with Radiolabeled Anti–Fibroblast Activation Protein Antibody Correlates with Severity of Arthritis

Abstract

SPECT/CT imaging with the anti-FAP antibody (111)In-28H1 specifically visualized arthritic joints with high resolution, and tracer accumulation correlated with the severity of the inflammation in murine experimental arthritis. Background uptake of the radiolabeled antibody was low, resulting in excellent image quality. (89)Zr-28H1 was less favorable for RA imaging because of an elevated bone uptake of (89)Zr. Future studies will focus on the potential role of 28H1 as a tool to monitor therapy response early on.