RT Journal Article
SR Electronic
T1 <sup>68</sup>Ga-Labeled Fibroblast Activation Protein Inhibitor (<sup>68</sup>Ga-FAPI) PET for Pancreatic Adenocarcinoma: Data from the <sup>68</sup>Ga-FAPI PET Observational Trial
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 1910
OP 1917
DO 10.2967/jnumed.122.264827
VO 64
IS 12
A1 Kessler, Lukas
A1 Hirmas, Nader
A1 Pabst, Kim M.
A1 Hamacher, Rainer
A1 Ferdinandus, Justin
A1 Schaarschmidt, Benedikt M.
A1 Milosevic, Aleksandar
A1 Nader, Michael
A1 Umutlu, Lale
A1 Uhl, Waldemar
A1 Reinacher-Schick, Anke
A1 Lugnier, Celine
A1 Witte, David
A1 Niedergethmann, Marco
A1 Herrmann, Ken
A1 Fendler, Wolfgang P.
A1 Siveke, Jens T.
YR 2023
UL http://jnm.snmjournals.org/content/64/12/1910.abstract
AB The fibroblast activation protein (FAP) is highly expressed on carcinoma-associated fibroblasts in the stroma of pancreatic cancer and thus is a promising target for imaging and therapy. Preliminary data on PET imaging with radiolabeled FAP inhibitors (FAPIs) demonstrate superior tumor detection. Here we assess the accuracy of FAP-directed PET in patients with pancreatic cancer. Methods: Of 64 patients with suspected or proven pancreatic cancer, 62 (97%) were included in the data analysis of the 68Ga-FAPI PET observational trial (NCT04571086). All of these patients underwent contrast-enhanced CT, and 38 patients additionally underwent 18F-FDG PET. The primary study endpoint was the association of 68Ga-FAPI PET uptake intensity and histopathologic FAP expression. Secondary endpoints were detection rate, diagnostic performance, interreader reproducibility, and change in management. Datasets were interpreted by 2 masked readers. Results: The primary endpoint was met: The association between 68Ga-FAPI SUVmax and histopathologic FAP expression was significant (Spearman r, 0.48; P = 0.04). For histopathology-validated lesions, 68Ga-FAPI PET showed high sensitivity and positive predictive values (PPVs) on per-patient (sensitivity, 100%; PPV, 96.3%) and per-region (sensitivity, 100%; PPV, 97.0%) bases. In a head-to-head comparison versus 18F-FDG or contrast-enhanced CT, 68Ga-FAPI detected more tumor on a per-lesion (84.7% vs. 46.5% vs. 52.9%), per-patient (97.4% vs. 73.7% vs. 92.1%), or per-region (32.6% vs. 18.8% vs. 23.7%) basis, respectively. 68Ga-FAPI PET readers showed substantial overall agreement on the basis of the Fleiss κ: primary κ, 0.77 (range, 0.66–0.88). Minor and major changes in clinical management occurred in 5 patients (8.4%) after 68Ga-FAPI PET. Conclusion: We confirmed an association of 68Ga-FAPI PET SUVmax and histopathologic FAP expression in pancreatic cancer patients. Additionally, we found high detection rate and diagnostic accuracy, superior to those of 18F-FDG PET/CT. 68Ga-FAPI might become a powerful diagnostic tool for pancreatic cancer work-up.