18 F-FAPI-04 Outperforms 18 F-FDG PET/CT in Clinical Assessments of Patients with Pancreatic Adenocarcinoma.

Accurate diagnosis and staging are crucial for selecting treatment for patients with pancreatic ductal adenocarcinoma (PDAC). The desmoplastic responses associated with PDAC are often characterized by hypometabolism. Here, we investigated ¹⁸ F-fibroblast activation protein inhibitor (FAPI)-04 PET/CT in evaluation of PDAC and compared the findings with those obtained using ¹⁸ F-FDG. Methods: Sixty-two PDAC patients underwent ¹⁸ F-FAPI-04 PET/CT and ¹⁸ F-FDG PET/CT. Identification of primary lesions, lymph node (LN) metastasis, and distant metastasis (DM) by these methods was evaluated, and TNM staging was performed. Correlation between SUV _max of the primary lesion and treatment response was explored in patients who received systemic therapy. Results: ¹⁸ F-FAPI-04 PET/CT identified all patients with PDAC; ¹⁸ F-FDG PET/CT missed 1 patient. Tracer uptake was higher in ¹⁸ F-FAPI-04 PET/CT than in ¹⁸ F-FDG PET/CT in primary tumors (10.63 vs. 2.87, P < 0.0001), LN metastasis (2.90 vs. 1.43, P < 0.0001), and DM (liver, 6.11 vs. 3.10, P = 0.002; peritoneal, 4.70 vs. 2.08, P = 0.015). The methods showed no significant difference in the T staging category, but the N and M values were significantly higher for ¹⁸ F-FAPI-04 PET/CT than for ¹⁸ F-FDG PET/CT ( P = 0.002 and 0.008, respectively). Thus, 14 patients were upgraded, and only 1 patient was downgraded, by ¹⁸ F-FAPI-04 PET/CT compared with ¹⁸ F-FDG PET/CT. A high SUV _max of the primary tumor did not correlate with treatment response for either ¹⁸ F-FAPI-04 or ¹⁸ F-FDG. Conclusion: ¹⁸ F-FAPI-04 PET/CT performed better than ¹⁸ F-FDG PET/CT in identification of primary tumors, LN metastasis, and DM and in TNM staging of PDAC.
(© 2024 by the Society of Nuclear Medicine and Molecular Imaging.)