Clinical prospective study of Gallium 68 (68Ga)–labeled fibroblast-activation protein inhibitor PET/CT in the diagnosis of biliary tract carcinoma

Abstract

To investigate the 68 Ga-labeled broblast-activation protein inhibitor ( 68 Ga-FAPI) PET/CT diagnosis performance in biliary tract carcinoma (BTC), and analyze the association between 68 Ga-FAPI PET/CT and clinical indexes. MethodsA prospective study (NCT 05264688) was performed between January 2022 through July 2022. Fifty participants were scanned using 68 Ga-FAPI and 18 F-FDG PET/CT and acquired pathological tissue.We employed the Wilcoxon signed-rank test to compare the uptake of 68 Ga-FAPI and 18 F-FDG, and the McNemar test was used to compare the diagnostic e cacy between the two tracers. Spearman or Pearson correlation was used to assess the association between 68 Ga-FAPI PET/CT and clinical indexes. ResultsIn total, 47 participants (mean age 59.09±10.98 [range 33-80 years]) were evaluated. The 68 Ga-FAPI detection rate was greater than 18 F-FDG in primary tumors (97.62% vs. 85.71%), nodal metastases (90.05% vs. 87.06%), distant metastases (100% vs. 83.67%). The uptake of 68 Ga-FAPI was higher than 18 F-FDG in primary lesions (intrahepatic cholangiocarcinoma: 18.95±7.47 vs. 11.86±0.70, p=0.001; extrahepatic cholangiocarcinoma:14.57±6.16 vs. 8.80±4.74, p=0.004), abdomen and pelvic cavity nodal metastases (6.91±6.56 vs. 3.94±2.83, p<0.001), distant metastases (pleural, peritoneum, omentum, and mesentery: 6.37±4.21 vs. 4.50±1.96, p=0.01; Bone: 12.15±6.43 vs. 7.51±4.54, p=0.008). There was a signi cant correlation between 68 Ga-FAPI uptake and FAP expression (Spearman r=0.432, p=0.009), carcinoembryonic antigen (CEA) (Pearson r=0.364, p=0.012), and platelet (PLT) (Pearson r=0.35, p=0.016). Meanwhile, a signi cant relationship between 68 Ga-FAPI metabolic tumor volume (MTV) and carbohydrate antigen199 (CA199) (Pearson r=0.436, p=0.002) was con rmed. Conclusion68 Ga-FAPI preceded 18 F-FDG in diagnosing BTC to a certain extent. The correlation between 68 Ga-FAPI PET/CT indexes and FAP expression, CEA, PLT, and CA199 were con rmed. Author ContributionsAll authors contributed to the study conception and design. Yuan Yufeng, He Yong and Zhang Zhonglin designed the clinical research, Jiang Yaqun and Xia Xigang conducted the literature search,

FAP-targeted PET imaging in gastrointestinal malignancies: a comprehensive review

“…In a recent study including 6 intrahepatic and 4 extrahepatic CCC patients, FAPI PET sensitivity surpassed FDG PET in detecting lymph node and distant metastatic lesions [ 83 ]. Similar findings were reported by Jinghua et al in primary tumour and metastases detection on FAPI PET in a cohort of intra/extrahepatic CCC and gall bladder carcinoma [ 82 ] (Supplementary Table 1- Additional file 1 ).…”

“…In all studies comparing the FAPI PET and FDG PET in CCC lesions, significantly higher primary tumour SUVmax (SUVmax 19.8 vs. 4.9 [ 77 ], SUVmax 14.1 vs. 9.2 [ 78 ], SUVmax 16.5 vs. 4.2 [ 79 ], SUVmax 19 vs. 11.9 [ 82 ], SUVmax 14.5 vs. 5.2 [ 83 ]) and TBR values (TBR 21.1 vs. 1.5 [ 77 ], TBR 10.9 vs. 2.5 [ 78 ], TBR 7.0 vs. 1.5 [ 79 ], TBR 20.6 vs. 4.6 [ 82 ], TBR(blood) 9.7 vs. 2.4 and TBR(liver) 12.1 vs. 1.9 [ 83 ]) on FAPI PET were declared [ 77 – 79 , 83 ].…”