35th Annual Congress of the European Association of Nuclear Medicine, Barcelona, Spain, 15 - 19 October 2022, pp.41
Aim/Introduction:This study compares the diagnostic performance
of [68Ga]Ga-FAPI04 (FAPI) and [18F]F-FDG PET/CT in patients
with known or suspected hepatocellular carcinoma (HCC) and
intrahepatic cholangiocarcinoma (ICC). Materials and Methods:
Thirty-two patients undergoing FAPI, FDG PET/CT, and contrastenhanced MRI (n=28) due to suspected or known HCC (n=14) and
ICC (n=18) were included. All images were evaluated, documenting
all lesions with abnormal uptake and classified as primary liver
lesions and extrahepatic metastases. Histopathological examination
(biopsy/surgery) of liver lesions was performed in 20 patients and,
together with MRI, was admitted as the reference standard for the
final diagnosis. Maximum standardized uptake values (SUVmax) of
all lesions and target-background ratio (TBR) of liver lesions were
measured, and the sensitivity of both modalities was calculated.
Results: The cohort included 32 patients (18 male, 14 female, mean
age 59.2±12.8 years). The median AFP, CEA and Ca19-9 levels were
545.7 ng/ml (1.7-147150), 48.5 ng/ml (1-611) and 1649 U/ml (5-
13822), respectively. FDG and FAPI were positive in 21 (65.6%) and
22 (%68.7) patients and in 107 and 160 lesions, of which 98 and
156 were true positive, respectively. Median SUVmax and TBR were
higher on FAPI than FDG (12.1 vs. 6.0 and 5.3 vs. 2.6, respectively).
The sensitivity of [68Ga]Ga-FAPI-04 and [18F]FDG/CT for detecting
primary liver tumors were 62.5% and %56.2, respectively. The
per-lesion detection rate of [68Ga]Ga-FAPI-04 PET/CT was higher
than [18F]FDG PET/CT (71.6% vs. 58.4%) for intrahepatic lesions.
Regarding the extrahepatic metastases, the per-lesion detection
rate of [68Ga]Ga-FAPI-04 PET/CT was also higher than [18F]-FDG
PET/CT (96.7% vs. 54.4%) Conclusion: This preliminary study shows
that the sensitivity of [68Ga]Ga-FAPI-04 PET/CT is better than [18F]-
FDG PET/CT at identifying liver lesions, particularly for metastatic
disease, and its use may improve tumor staging, implementation
of necessary treatment modifications and theranostic approaches.