Dual-tracer PET/CT protocol with [<sup>18</sup>F]-FDG and [<sup>68</sup>Ga]Ga-FAPI-46 for cancer imaging - a proof of concept.
Katrin Sabine Roth, Conrad‐Amadeus Voltin, Lutz van-Heek, Simone Wegen, Klaus Schomaecker, Thomas Fischer, Simone Marnitz, Alexander Drzezga, Carsten Kobe
Abstract
Imaging studies with PET tracers acting as fibroblast activation protein inhibitors (FAPI) show promising results that could usefully complement [<sup>18</sup>F]-FDG in cancer imaging. <b>Methods:</b> All patients received [<sup>18</sup>F]-FDG-PET/CT and dual-tracer PET/CT after additional injection of [<sup>68</sup>Ga]Ga-FAPI-46 following the [<sup>18</sup>F]-FDG-PET/CT. Two readers visually compared detection rate and analyzed target-to-background uptake ratios (TBRs) for tumor and metastatic tissue in single and dual-tracer PET/CT. <b>Results:</b> Detection rate in dual-tracer PET/CT was visually as good as that in single-tracer PET/CT in four patients and superior in two patients, whereas TBRs were significantly higher in dual-tracer PET/CTs. <b>Conclusion:</b> We demonstrate the feasibility and potential of dual-tracer [<sup>18</sup>F]-FDG-[<sup>68</sup>Ga]Ga-FAPI-46-PET/CT administered within a single session. The dual-tracer approach may have superior sensitivity to [<sup>18</sup>F]-FDG-PET/CT alone without compromising individual assessment of either scan.