RT Journal Article
SR Electronic
T1 Staging Liver Fibrosis by Fibroblast Activation Protein Inhibitor PET in a Human-Sized Swine Model
JF Journal of Nuclear Medicine
JO J Nucl Med
FD Society of Nuclear Medicine
SP 1956
OP 1961
DO 10.2967/jnumed.121.263736
VO 63
IS 12
A1 Ali Pirasteh
A1 Sarvesh Periyasamy
A1 Jennifer Jean Meudt
A1 Yongjun Liu
A1 Laura M. Lee
A1 Kyle M. Schachtschneider
A1 Lawrence B. Schook
A1 Ron C. Gaba
A1 Lu Mao
A1 Adnan Said
A1 Alan Blair McMillan
A1 Paul F. Laeseke
A1 Dhanansayan Shanmuganayagam
YR 2022
UL http://jnm.snmjournals.org/content/63/12/1956.abstract
AB Current methods of staging liver fibrosis have notable limitations. We investigated the utility of PET in staging liver fibrosis by correlating liver uptake of 68Ga-labeled fibroblast activation protein inhibitor (FAPI) with histology in a human-sized swine model. Methods: Five pigs underwent baseline 68Ga-FAPI-46 (68Ga-FAPI) PET/MRI and liver biopsy, followed by liver parenchymal embolization, 8 wk of oral alcohol intake, endpoint 68Ga-FAPI PET/MRI, and necropsy. Regions of interest were drawn on baseline and endpoint PET images, and SUVmean was recorded. At the endpoint, liver sections corresponding to regions of interest were identified and cut out. Fibrosis was histologically evaluated using a modified METAVIR score for swine liver and quantitatively using collagen proportionate area (CPA). Box-and-whisker plots and linear regression were used to correlate SUVmean with METAVIR score and CPA, respectively. Results: Liver 68Ga-FAPI uptake strongly correlated with CPA (r = 0.89, P < 0.001). 68Ga-FAPI uptake was significantly and progressively higher across F2 and F3/F4 fibrosis stages, with a respective median SUVmean of 2.9 (interquartile range [IQR], 2.7–3.8) and 7.6 (IQR, 6.7–10.2) (P < 0.001). There was no significant difference between 68Ga-FAPI uptake of baseline liver and endpoint liver sections staged as F0/F1, with a respective median SUVmean of 1.7 (IQR, 1.3–2.0) and 1.7 (IQR, 1.5–1.8) (P = 0.338). Conclusion: The strong correlation between liver 68Ga-FAPI uptake and the histologic stage of liver fibrosis suggests that 68Ga-FAPI PET can play an impactful role in noninvasive staging of liver fibrosis, pending validation in patients.