68Ga-FAPI-2 and 68Ga-FAPI-4 at 10 minutes, 1 hour, and 3 hours after injection. Rapid tumor targeting and fast blood clearance are followed by long plateau phase without relevant change in image contrast (top). In comparison to 68Ga-FAPI-2, 68Ga-FAPI-4 is characterized by prolonged tumor retention time (bottom). LW = lumbar body.
Giesel FL, Kratochwil C, Lindner T, et al.