⁶⁸ Ga FAPI-46 Fibroblast Activation Protein Inhibitor Uptake in Graves’ Ophthalmopathy

Fibroblast activation protein inhibitor (FAPI) PET/CT has emerged as a novel imaging technique for fibroblast-driven pathology. Orbital fibroblast activation is central to the pathogenesis of Graves’ ophthalmopathy (GO), making fibroblast activation protein (FAP) a mechanistically appropriate molecular target. We report a case of a 59-year-old female with steroid-refractory active GO (clinical activity score 6/7) who underwent ⁶⁸ Ga ⁴⁶ FAPI PET/CT, which demonstrated tracer accumulation in bilateral extraocular muscles with a topographic distribution consistent with known disease anatomy. Imaging findings correlated with high disease activity despite immunosuppressive therapy, suggesting