Clinical value of [F]AlF-NOTA-FAPI-04 PET/CT for assessing early-stage liver fibrosis in adult liver transplantation recipients compared with chronic HBV patients.

Aims: To investigate the clinical value and performance of [F]AlF-NOTA-FAPI-04 PET/CT in assessing early-stage liver fibrosis in liver transplantation (LT) recipients.

Methods: A prospective study including 17 LT recipients and 12 chronic Hepatitis B (CHB) patients was conducted. All patients received liver biopsy, transient elastography (TE), and [F]AlF-NOTA-FAPI-04 PET/CT. On [F]AlF-NOTA-FAPI-04 PET/CT scans, the liver parenchyma's maximum standardized uptake values (SUV) were measured. The receiver operating characteristic (ROC) curve analysis was applied to determine the diagnostic efficacy of [F]AlF-NOTA-FAPI-04 PET/CT in early-stage liver fibrosis (S1-S2) compared with the diagnostic performance of TE.

Results: Among those 29 patients enrolled in this study, 15(51.7%) had fibrosis S0, 10(34.5%) had S1, and 4(13.8%) had S2, respectively. The SUV of patients with early-stage liver fibrosis was significantly higher than those without liver fibrosis in LT recipients and CHB patients (P = 0.004, P = 0.02). In LT recipients, a SUV cut-off value of 2.0 detected early-stage liver fibrosis with an AUROC of 0.92 (P = 0.006), and a liver stiffness measurements (LSM) score cut-off value of 8.2 kPa diagnosed early-stage liver fibrosis with an AUROC of 0.80 (P = 0.012). In CHB patients, a SUV cut-off value of 2.7 detected early-stage liver fibrosis with an AUROC of 0.94 (P < 0.001) and an LSM scores cut-off value of 8.4 kPa diagnosed early-stage liver fibrosis with an AUROC of 0.91 (P < 0.001).

Conclusion: [F]AlF-NOTA-FAPI-04 PET/CT could be applied to evaluate early-stage liver fibrosis in LT recipients and CHB patients properly, with the potential additional advantages in monitoring and predicting complications after LT.