A pilot human-based study of 68Ga-FAPI-04 PET/CT in staging liver fibrosis and preliminary comparison to FIB-4 and fibroscan

To explore the potential value of 68Ga-FAPI-04 PET/CT in staging liver fibrosis of patients with chronic liver diseases, and to preliminarily compare its diagnostic performance with Fibroscan and the fibrosis-4 (FIB-4) index. The single-center prospective study enrolled participants with chronic liver diseases who had undergone liver biopsy. 68Ga-FAPI-04 PET/CT grading is conducted through a scoring system: TBRliver−to−blood greater than 2 as F4, TBRliver−to−blood between 1 and 2 as F2/3, and TBRliver−to−blood less than 1 as F0/1. The diagnostic performance of 68Ga-FAPI-04 PET/CT was preliminarily compared with Fibroscan and FIB-4 using accuracy and weighted Kappa values. A total of 14 participants (8 men, 6 women) were enrolled. According to the METAVIR scoring system, 6 participants (43%) had F0/1 fibrosis, 4 (28%) had F2, and 4 (28%) had F4. The TBRliver−to−blood in the F0/1 group (0.83 ± 0.07) was significantly lower than that in the F4 group (2.12 ± 0.78) (P = 0.010). Using a TBRliver−to−blood > 1 for 68Ga-FAPI-04 to diagnose F ≥ 2 fibrosis yielded a sensitivity of 87.5%, specificity of 83.3%, and PPV of 87.5%. Both FIB-4 and Fibroscan correctly classified 10/14 (71.4%) participants (weighted Kappa values: 0.696 and 0.598, respectively). 68Ga-FAPI-04 PET/CT successfully differentiated 12/14 (85.7%) participants (weighted Kappa = 0.841). The results of this preliminary study suggest that 68Ga-FAPI-04 PET/CT may be an effective non-invasive method for assessing liver fibrosis and could potentially outperform FIB-4 and Fibroscan. Further clinical trials are warranted for validation.