⁶⁸Ga-conjugated fibroblast activation protein inhibitor (⁶⁸Ga-FAPI) has become an attractive agent for PET. This study aimed to compare ⁶⁸Ga-FAPI-46 PET/CT with ¹⁸F-FDG PET/CT for detecting primary cancer and metastatic lesions in patients with head and neck squamous cell carcinoma (HNSCC). Methods: Twelve patients and 28 patients with HNSCC underwent ⁶⁸Ga-FAPI-46 and ¹⁸F-FDG PET/CT for initial staging and recurrence detection, respectively. The concordance and diagnostic accuracy of both tracers were analyzed. Semiquantitative parameters, including SUV_max, SUV_mean, and tumor-to-background ratio, were compared. Fibroblast activation protein (FAP) expression tumor volume and total lesion FAP expression of ⁶⁸Ga-FAPI-46 were compared with metabolic tumor volume and total lesion glycolysis of ¹⁸F-FDG, respectively. Differences between semiquantitative parameters were analyzed using paired t testing. Results: ⁶⁸Ga-FAPI-46 PET/CT was 83.3% and 96.4% concordant with ¹⁸F-FDG PET/CT for initial staging and recurrence detection, respectively. Eighteen lesions had histopathologic validation, and both tracers displayed 100% sensitivity, 50% specificity, and 94.4% accuracy for lesion-based analysis. FAP expression tumor volume was greater than metabolic tumor volume (P < 0.05), but no significant differences were observed for the other parameters. Conclusion: ⁶⁸Ga-FAPI-46 PET/CT showed good concordance with, and comparable diagnostic performance to, ¹⁸F-FDG PET/CT for initial staging and recurrence detection in HNSCC patients.

⁶⁸ Ga结合成纤维细胞活化蛋白抑制剂（⁶⁸ Ga-FAPI）已成为PET的有吸引力的药剂。本研究旨在比较⁶⁸ Ga-FAPI-46 PET/CT 与¹⁸ F-FDG PET/CT 在检测头颈部鳞状细胞癌 (HNSCC) 患者的原发性癌和转移性病变方面的效果。方法： 12 名 HNSCC 患者和 28 名 HNSCC 患者分别接受了⁶⁸ Ga-FAPI-46 和¹⁸ F-FDG PET/CT 进行初始分期和复发检测。分析了两种示踪剂的一致性和诊断准确性。半定量参数，包括 SUV _max、 SUV _mean和肿瘤与背景的比率进行了比较。^{分别比较了68} Ga-FAPI-46 的成纤维细胞活化蛋白 (FAP) 表达肿瘤体积和总病灶 FAP 表达与代谢肿瘤体积和总病灶糖酵解¹⁸ F-FDG。使用配对t检验分析半定量参数之间的差异。结果： ^{68 Ga-FAPI-46 PET/CT 与18} F-FDG PET/CT 的初始分期和复发检测的一致性分别为 83.3% 和 96.4% 。18 个病灶经过组织病理学验证，两种示踪剂均显示 100% 的敏感性、50% 的特异性和 94.4% 的基于病灶分析的准确度。FAP表达肿瘤体积大于代谢肿瘤体积（P < 0.05），但其他参数无显着差异。结论： ⁶⁸ Ga-FAPI-46 PET/CT在 HNSCC 患者的初始分期和复发检测中表现出与¹⁸ F-FDG PET/CT良好的一致性和可比性的诊断性能。