Comparison of (68)Ga-FAPI and (18)F-FDG PET/CT in the Evaluation of Patients With Newly Diagnosed Non-Small Cell Lung Cancer

PURPOSE: Several studies have demonstrated that (68)Ga-FAPI PET/CT shows high intratumoral tracer uptake and low normal tissue uptake, allowing for excellent visualization of cancer. The purpose of this study was to compare the ability of (68)Ga-FAPI and (18)F-FDG PET/CT for the evaluation of newly diagnosed NSCLC. MATERIALS AND METHODS: A prospective analysis of 28 individuals with histopathologically newly confirmed NSCLC that underwent (68)Ga-FAPI and (18)F-FDG PET/CT was conducted. The performance of two imaging modalities was compared based upon visual assessment, rates of cancer detection, and semi-quantitative parameters (target-to-background ratio [TBR], maximum standard uptake value [SUVmax]) for both primary tumors and metastases. RESULTS: In total, this study enrolled 28 participants (13 male, 15 female; median age: 60.5 years, range: 34 – 78 years. <u>For primary tumors, (68)Ga-FAPI and (18)F-FDG PET/CT have similar detection performance (28 vs. 27). However, (68)Ga-FAPI PET/CT was found to more effectively evaluate most metastases as compared to (18)F-FDG PET/CT. (68)Ga-FAPI PET/CT detecting more metastases present within the lymph nodes (53 vs. 49), pleura (8 vs. 7), liver (4 vs. 1), and bone (41 vs. 35).</u> The SUVmax and TBR values for (68)Ga-FAPI were substantially superior to those for (18)F-FDG in lymph node, pleural, and bone metastases. While the SUVmax for these two imaging approaches was comparable for hepatic metastases, (68)Ga-FAPI exhibited a significantly higher TBR in relation to that of (18)F-FDG. In addition, (68)Ga-FAPI PET/CT demonstrates excellent N (80% [8/10]) and M (92.9% [26/28]) staging accuracy in NSCLC patients. CONCLUSIONS: (68)Ga-FAPI PET/CT as an examination modality is excellent for evaluation of newly diagnosed NSCLC. (68)Ga-FAPI PET/CT improves the detection rates of most metastases and facilitating the superior staging of patients with newly diagnosed NSCLC, relative to that achieved by (18)F-FDG PET/CT.