Comparison of the diagnostic accuracy between 18F-FAPI-04 PET/CT and 18F-FDG PET/CT in the clinical stage IA of lung adenocarcinoma

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Key findings

• The present study revealed a statistically significant increase in the maximum standardized uptake value and the tumor-to-background ratio of fluorine 18-labeled fibroblast activation protein inhibitor (¹⁸F-FAPI-04) compared with fluorine-18 labeled-fluorodeoxyglucose (¹⁸F-FDG) for stage IA lung adenocarcinoma (LUAD) (P<0.05).

What is known and what is new?

• ¹⁸F-FDG positron emission tomography/computed tomography (PET/CT) is used for the staging and restaging of lung cancer, however, false-negative results may occur when evaluating nodules measuring below 1.0 cm (T1a), adenocarcinoma in situ, or minimally invasive adenocarcinoma.

• We compared the diagnostic value of ¹⁸F-FDG PET/CT and ¹⁸F-FAPI-04 PET/CT imaging in stage IA LUADs while assessing fibroblast activating protein (FAP) expression using immunohistochemistry in resected specimens.

What is the implication, and what should change now?

• ¹⁸F-FAPI-04 PET/CT may be superior to ¹⁸F-FDG PET/CT for detecting stage IA LUAD lesions. ¹⁸F-FAPI-04 uptake in stage IA LUAD was significantly and positively correlated with ex vivo FAP expression.

Publication: Liang HX, Huang QW, He YM, Mai YQ, Chen ZL, Wang BP, Fang N, Hu JF, Li X, Zhang N, Liu ET, Li XC. Comparison of the diagnostic accuracy between ¹⁸F-FAPI-04 PET/CT and ¹⁸F-FDG PET/CT in the clinical stage IA of lung adenocarcinoma. J Thorac Dis 2025;17(2):661-675. doi: 10.21037/jtd-24-1658