Imaging with Ga-68-FAPI PET/CT: Results from a FAPI Registry Study

Ziel/Aim FAPI ligands (fibroblast activation protein inhibitor), a novel class of radiotracers for PET/CT imaging, demonstrated promising preclinical and clinical results. FAP is overexpressed by cancer-associated fibroblasts of several tumor entities and hence can be targeted for diagnostic purposes. Since October 2018, oncology patients undergoing Ga-68-FAPI PET/CT diagnostic imaging at our department have been included in our local FAPI registry. We hereby present an overview of the tumor entities and their uptake across a 3-year period.

Methodik/Methods Patients included underwent Ga-68-FAPI PET/CT imaging for staging or re-staging purposes for various tumor entities. All PET/CT scans were performed at a median of 14.5 minutes after injection of a median of 112 MBq of Ga-68-FAPI-46 or a median of 149 MBq of Ga-68-FAPI-04. Tumor uptake was quantified by SUV_max, SUV_mean, peak and tumor volume (40% isocontour). Demographic, clinical and lab data are collected and routinely updated as patients are followed up in our registry study.

Ergebnisse/Results A total of 324 patients with 21 different tumor entities were included in our FAPI-PET registry as of October 2021. The median age of patients is 59 years (range, 19-93 years), the male-female ratio is 1.08:1, and the majority of patients underwent Ga-68-FAPI PET/CT for restaging purposes (69%). The most common tumors were sarcomas (N=131, median SUV_max=10.9, IQR=12.6), pancreatic adenocarcinomas (N=67, median SUV_max=13.5, IQR=9.9), glioblastomas (N=22, median SUV_max=4.9, IQR=2.1), lung cancer (N=13, median SUV_max=7.4, IQR=6.1) and cholangiocellular carcinoma (N=11, median SUV_max=20.9, IQR=15.6).

Schlussfolgerungen/Conclusions Several prevalent tumor entities present with high and rapid uptake as well as image contrast on Ga-68-FAPI PET/CT. Selective tumor uptake using this imaging modality paves the way for tumor staging and characterization and opens the door for future radioligand therapy.

Publication History

Article published online:
14 April 2022