68Ga DOTA FAPI-46 Versus 18F FDG PET/CT in Non–small Cell Lung Cancer: A Direct Comparative Study

Propose of the Report: Considering the favorable characteristic of 68 Ga FAPI-PET/CT, this study is aimed to compare the findings of 68 Ga FAPI versus 18 F FDG-PET/CT for the evaluation of patients with newly diagnosed non–small cell lung cancer (NSCLC). Patients and Methods: Fourteen patients with pathology-proven NSCLC were enrolled in this study. The primary and metastatic lesions in 68 Ga FAPI-PET/CT images were compared with 18 F FDG-PET/CT one by one based on standardized uptake value (SUV)max calculation, tumor-to-background ratio (TBR), and visual assessment. Results: There was no statistically significant difference in the TBR of primary tumors. In patient-based analysis, 18 F FDG-PET/CT generally exhibited higher SUVmax than 68 Ga FAPI-PET/CT; however, these differences were not statistically significant. Conversely, 68 Ga FAPI-PET/CT demonstrated a higher TBR in mediastinal, abdominal lymph nodes, and bone metastatic lesions; again, none of these differences reached statistical significance. In lesion-based analysis, pulmonary nodules revealed higher 18 F FDG SUVmax and TBR compared with 68 Ga FAPI-PET/CT ( P <0.001 for both), significantly. Mediastinal lymph nodes showed significantly higher SUV max in 18 F FDG-PET/CT ( P <0.001). Bone and abdominal lymph nodes demonstrated higher TBR with 68 Ga FAPI than 18 F FDG-PET/CT ( P <001, P =0.008; respectively). Conclusions: 68 Ga DOTA-FAPI-46-PET/CT detection rate of primary and metastatic lesions of NSCLC is comparable to 18 F FDG PET/CT in terms of TNM staging, SUV max, and TBR, and potentially could detect more lesions than 18 F FDG PET/CT in bone metastases.