Dual-Tracer PET/CT Protocol with [F-18]-FDG and [Ga-68]Ga-FAPI-46 for Cancer Imaging: A Proof of Concept

Imaging studieswithPET tracers acting as fibroblast activation protein inhibitors (FAPIs) show promising results that could usefully complement [F-18]-FDG in cancer imaging. Methods: All patients received [F-18]-FDG PET/CT and dual-tracer PET/CT after an additional injection of [Ga-68]Ga-FAPI-46 after the [F-18]-FDG PET/CT. Two readers visually compared detection rate and analyzed target-to-background ratios for tumor and metastatic tissue in single- and dual-tracer PET/CT. Results: Detection rate in dual-tracer PET/CT was visually as good as that in single-tracer PET/CT in 4 patients and superior in 2 patients, whereas target-to-background ratios were significantly higher in dualtracer PET/CT. Conclusion: Dual-tracer [F-18]-FDG/[Ga-68]Ga-FAPI-46 PET/CT within a single session is feasible and has potential. The dualtracer approach may have superior sensitivity to [F-18]-FDG PET/CT alone without compromising individual assessment of either scan