Higher accuracy of [(68) Ga]Ga-DOTA-FAPI-04 PET/CT comparing with 2-[F-18]FDG PET/CT in clinical staging of NSCLC

Purpose This study aimed to explore the clinical staging performance of [(68) Ga]Ga-DOTA-FAPI-04 PET/CT compared with that of 2-[F-18]FDG PET/CT in non-small cell lung cancer (NSCLC) patients lesion by lesion. Methods A total of 134 diagnosed or suspected NSCLC patients were enrolled in the prospective study (ChiCTR2000038080); they received paired 2-[F-18]FDG PET/CT and [(68) Ga]Ga-DOTA-FAPI-04 PET/CT. Of these patients, the retrospective analysis of 74 NSCLC patients with pathological results was conducted from primary tumor (T) diagnosis, lymph node (N), and metastatic lesion (M) staging. The imaging characteristics of the lung nodules and suspected metastases were obtained and analyzed, and the staging performance of 2-[F-18]FDG PET/CT and [(68) Ga]Ga-DOTA-FAPI-04 PET/CT was compared. Results For T diagnosis, [(68) Ga]Ga-DOTA-FAPI-04 showed better diagnostic performance than 2-[F-18]FDG in 79 lung nodules of 72 patients, especially for nonsolid and small-dimension adenocarcinoma nodules. For N staging, 98 lymph nodes (LNs) with pathological results in 37 patients were analyzed. The SUVmax of [(68) Ga]Ga-DOTA-FAPI-04 in the nonmetastatic LNs was significantly lower than that in the metastatic LNs. Regarding metastatic LN identification, the calculated optimum cut-off value of [(68) Ga]Ga-DOTA-FAPI-04 SUVmax was 5.5, and the diagnostic accuracy using [(68) Ga]Ga-DOTA-FAPI-04 and 2-[F-18]FDG criteria was 94% and 30%, respectively (P < 0.001). For M staging, [(68) Ga]Ga-DOTA-FAPI-04 identified more lesions than 2-[F-18]FDG (257 vs. 139 lesions) in 14 patients with multiple metastases. Overall, the staging accuracy of [(68) Ga]Ga-DOTA-FAPI-04 was better than that of 2-[F-18]FDG in 52 patients with different pathological stages [43/52 (82.7%) vs. 27/52 (51.9%), P = 0.001]. Conclusion Compared with 2-[F-18]FDG PET/CT, [(68) Ga]Ga-DOTA-FAPI-04 PET/CT demonstrated better staging performance in NSCLC patients with different pathological stages, especially those with localized disease.