학술논문
Head-to-head intra-individual comparison of biodistribution and tumor uptake of 68Ga-FAPI and 18F-FDG PET/CT in cancer patients
Document Type
article
Author
Giesel, Frederik L; Kratochwil, Clemens; Schlittenhardt, Joel; Dendl, Katharina; Eiber, Matthias; Staudinger, Fabian; Kessler, Lukas; Fendler, Wolfgang P; Lindner, Thomas; Koerber, Stefan A; Cardinale, Jens; Sennung, David; Roehrich, Manuel; Debus, Juergen; Sathekge, Mike; Haberkorn, Uwe; Calais, Jeremie; Serfling, Sebastian; Buck, Andreas L
Source
European Journal of Nuclear Medicine and Molecular Imaging. 48(13)
Subject
Language
Abstract
PurposeFAPI ligands (fibroblast activation protein inhibitor), a novel class of radiotracers for PET/CT imaging, demonstrated in previous studies rapid and high tumor uptake. The purpose of this study is the head-to-head intra-individual comparison of 68Ga-FAPI versus standard-of-care 18F-FDG in PET/CT in organ biodistribution and tumor uptake in patients with various cancers.Material and methodsThis international retrospective multicenter analysis included PET/CT data from 71 patients from 6 centers who underwent both 68Ga-FAPI and 18F-FDG PET/CT within a median time interval of 10 days (range 1-89 days). Volumes of interest (VOIs) were manually drawn in normal organs and tumor lesions to quantify tracer uptake by SUVmax and SUVmean. Furthermore, tumor-to-background ratios (TBR) were generated (SUVmax tumor/ SUVmax organ).ResultsA total of 71 patients were studied of, which 28 were female and 43 male (median age 60). In 41 of 71 patients, the primary tumor was present. Forty-three of 71 patients exhibited 162 metastatic lesions. 68Ga-FAPI uptake in primary tumors and metastases was comparable to 18F-FDG in most cases. The SUVmax was significantly lower for 68Ga-FAPI than 18F-FDG in background tissues such as the brain, oral mucosa, myocardium, blood pool, liver, pancreas, and colon. Thus, 68Ga-FAPI TBRs were significantly higher than 18F-FDG TBRs in some sites, including liver and bone metastases.ConclusionQuantitative tumor uptake is comparable between 68Ga-FAPI and 18F-FDG, but lower background uptake in most normal organs results in equal or higher TBRs for 68Ga-FAPI. Thus, 68Ga-FAPI PET/CT may yield improved diagnostic information in various cancers and especially in tumor locations with high physiological 18F-FDG uptake.