Abstract
Objective We compared the diagnostic accuracies of 68Ga FAPI-04 PET/CT and 18F-FDG PET/CT for detecting liver metastases (LMs) in patients with different cancer
types.
Materials and Methods This retrospective study included 63 patients with liver lesions who underwent 18F-FDG PET/CT and 68Ga-FAPI-04 PET/CT between May 2020 and May 2022. Patients with histopathologically
confirmed primary diagnoses, data that could be accessed retrospectively, liver lesions
confirmed by biopsy over at least 3–6 months of follow-up (via ultrasonography, CT,
magnetic resonance imaging, PET/CT, or laboratory tests) were included. Patients with
secondary malignancies or primary liver malignancies, and/or who could not be followed-up,
were excluded.
Results Of the 63 total patients, 34 (54%) were female, and the mean age was 61 (30–92) years.
There were 582 LMs in 51 patients and 35 benign liver lesions in 20 (12 patients had
only benign and 8 both benign and malignant lesions). Of the 582 LMs, 472 (81.1%)
evidenced 18F-FDG uptake and 572 (98.2%) 68Ga-FAPI uptake. The diagnostic accuracies of 68Ga-FAPI PET/CT and 18F-FDG PET/CT were 98% and 82%, respectively (p < 0.001; McNemar test). When the LMs
were compared, the maximum standardized uptake (SUVmax) value was significantly higher
on 18F-FDG PET/CT than 68Ga-FAPI PET/CT (median: 6.0 vs. 5.4; p = 0.016). However, the LM-to-background ratio
(TBR) was significantly higher on 68Ga-FAPI PET/CT than 18F-FDG PET/CT (median: 4.1 vs. 2.1; p < 0.001).
Conclusion
68Ga-FAPI PET/CT detected more LMs than did 18F-FDG PET/CT, and TBR was significantly higher on 68Ga-FAPI PET/CT than 18F-FDG PET/CT.
Keywords
68Ga FAPI-04 -
18F-FDG - SUVmax - Liver Metastasis - TBR
