RT Journal Article
SR Electronic
T1 Fibroblast-Activation Protein PET and Histopathology in a Single-Center Database of 324 Patients and 21 Tumor Entities
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 711
OP 716
DO 10.2967/jnumed.122.264689
VO 64
IS 5
A1 Nader Hirmas
A1 Rainer Hamacher
A1 Miriam Sraieb
A1 Marc Ingenwerth
A1 Lukas Kessler
A1 Kim M. Pabst
A1 Francesco Barbato
A1 Katharina Lueckerath
A1 Stefan Kasper
A1 Michael Nader
A1 Hans-Ulrich Schildhaus
A1 Claudia Kesch
A1 Bastian von Tresckow
A1 Christine Hanoun
A1 Hubertus Hautzel
A1 Clemens Aigner
A1 Martin Glas
A1 Martin Stuschke
A1 Sherko Kümmel
A1 Philipp Harter
A1 Celine Lugnier
A1 Waldemar Uhl
A1 Marco Niedergethmann
A1 Boris Hadaschik
A1 Viktor Grünwald
A1 Jens T. Siveke
A1 Ken Herrmann
A1 Wolfgang P. Fendler
YR 2023
UL http://jnm.snmjournals.org/content/64/5/711.abstract
AB We present an overview of our prospective fibroblast-activation protein inhibitor (FAPI) registry study across a 3-y period, with head-to-head comparison of tumor uptake in 68Ga-FAPI and 18F-FDG PET, as well as FAP immunohistochemistry. Methods: This is an interim analysis of the ongoing 68Ga-FAPI PET prospective observational trial at our department. Patients who underwent clinical imaging with 68Ga-FAPI PET between October 2018 and October 2021 were included. Tracer uptake was quantified by SUVmax for tumor lesions and by SUVmean for normal organs. PET tumor volume (40% isocontour) and tumor-to-background ratios were calculated. Correlation between SUVmax and FAP staining in tissue samples was analyzed. Results: In total, 324 patients with 21 different tumor entities underwent 68Ga-FAPI imaging; 237 patients additionally received 18F-FDG PET. The most common tumor entities were sarcoma (131/324, 40%), pancreatic cancer (67/324, 21%), and primary tumors of the brain (22/324, 7%). The mean primary tumor SUVmax was significantly higher for 68Ga-FAPI than 18F-FDG among pancreatic cancer (13.2 vs. 6.1, P < 0.001) and sarcoma (14.3 vs. 9.4, P < 0.001), and the same was true for mean SUVmax in metastatic lesions of pancreatic cancer (9.4 vs. 5.5, P < 0.001). Mean primary tumor maximum tumor-to-background ratio was significantly higher for 68Ga-FAPI than 18F-FDG across several tumor entities, most prominently pancreatic cancer (14.7 vs. 3.0, P < 0.001) and sarcoma (17.3 vs. 4.7, P < 0.001). Compared with 18F-FDG, 68Ga-FAPI showed superior detection for locoregional disease in sarcoma (52 vs. 48 total regions detected) and for distant metastatic disease in both sarcoma (137 vs. 131) and pancreatic cancer (65 vs. 57), respectively. Among 61 histopathology samples, there was a positive correlation between 68Ga-FAPI SUVmax and overall FAP immunohistochemistry score (r = 0.352, P = 0.005). Conclusion: 68Ga-FAPI demonstrates higher absolute uptake in pancreatic cancer and sarcoma, as well as higher tumor-to-background uptake along with improved tumor detection for pancreatic cancer, sarcoma, and other tumor entities when compared with 18F-FDG. 68Ga-FAPI is a new tool for tumor staging with theranostic potential.