放射性药物[18F]AlF-NOTA-FAPI-04因其相对较长的半衰期是68Ga-FAPI的有希望的替代品。本研究旨在评估[18F]AlF-NOTA-FAPI-04 PET/CT在诊断各种类型的胃肠系统肿瘤的原发性和转移性病灶方面与18F-FDG PET/CT相比的临床实用性。纳入了胃肠系统恶性肿瘤的患者进行前瞻性研究。所有患者在一周内同时接受了18F-FDG和18F-FAPI-04 PET/CT扫描，其中44例（73.3%）用于癌症分期，16例（26.7%）用于肿瘤再分期。评估了原发肿瘤的诊断效能，以及淋巴结和远处转移的存在和数量。肿瘤摄取通过最大标准摄取值（SUVmax）进行量化。对于原发肿瘤的检测，18F-FDG PET/CT的诊断敏感性为72.7%，而18F-FAPI-04 PET/CT的诊断敏感性为97.7%。基于淋巴结分析，18F-FAPI-04 PET/CT在诊断转移性淋巴结的敏感性、特异性和准确性分别为91.89%、92.00%和91.96%，明显高于18F-FDG PET/CT（79.72%、81.33%和80.80%）。18F-FAPI-04 PET/CT在检测脑（7对3）、肝（39对20）、骨（79对51）、肺（11对4）和腹膜癌（48对22）的可疑转移方面超过了18F-FDG PET/CT。基于患者分析，在所有患者（91.7%对76.7%）、初始分期组（90.9%对79.5%）和再分期组（93.8%对68.7%）中观察到不同的诊断准确性（18F-FAPI-04与18F-FDG PET/CT）。此外，18F-FAPI-04 PET/CT在31.7%的患者中修正了最终诊断，与18F-FDG PET/CT相比，对21.7%的患者的临床管理进行了改变。18F-FAPI-04 PET/CT在描绘原发胃肠肿瘤和检测可疑转移病灶方面优于18F-FDG PET/CT，这是由于其较高的靶区对背景比（TBR）。此外，18F-FAPI-04 PET/CT可以为肿瘤分期提供有价值的指导，从而对患者管理产生潜在影响。© 2023年作者。

The radiopharmaceutical [18F]AlF-NOTA-FAPI-04 presents a promising alternative to 68 Ga-FAPI owing to its relatively longer half-life. This study aimed to evaluate the clinical usefulness of [18F]AlF-NOTA-FAPI-04 PET/CT for the diagnosis of primary and metastatic lesions in various types of gastrointestinal system cancers, compared with 18F-FDG PET/CT.Patients diagnosed with gastrointestinal system malignancies were prospectively enrolled. All patients underwent both 18F-FDG and 18F-FAPI-04 PET/CT scans within one week, with 44 (73.3%) for cancer staging and 16 (26.7%) for tumor restaging. Diagnostic efficacy of the primary tumor, as well as the presence and number of lymph nodes and distant metastases, were assessed. Tumor uptake was quantified by the maximum standard uptake value (SUVmax).For detection of primary tumor, the diagnostic sensitivity of 18F-FDG PET/CT was 72.7%, while it was 97.7% for 18F-FAPI-04 PET/CT. Based on per-lymph node analysis, the sensitivity, specificity, and accuracy of 18F-FAPI-04 PET/CT in diagnosing metastatic lymph nodes were 91.89%, 92.00%, and 91.96%, respectively. These values were notably higher than those 18F-FDG PET/CT (79.72%, 81.33% and 80.80%, respectively). The 18F-FAPI-04 PET/CT surpassed 18F-FDG PET/CT in detecting suspected metastases in the brain (7 vs. 3), liver (39 vs. 20), bone (79 vs. 51), lung (11 vs. 4), and peritoneal carcinoma (48 vs. 22). Based on per-patient analysis, differential diagnostic accuracies (18F-FAPI-04 vs. 18F-FDG PET/CT) were observed in all patients (91.7% vs. 76.7%), the initial staging group (90.9% vs. 79.5%), and the re-staging group (93.8% vs. 68.7%). Additionally, 18F-FAPI-04 PET/CT revised final diagnosis in 31.7% of patients, contrasting with 18F-FDG PET/CT, and prompted changes in clinical management for 21.7% of the patients.18F-FAPI-04 PET/CT outperforms 18F-FDG PET/CT in delineating the primary gastrointestinal tumors and detecting suspected metastatic lesions due to a higher target-to-background ratio (TBR). Moreover, 18F-FAPI-04 PET/CT could provide valuable guidance for tumor staging, thereby having a potential impact on patient management.© 2023. The Author(s).