我们进行了一项前瞻性研究，使用18F-氟脱氧葡萄糖（18F-FDG）和68Ga-DOTA-FAPI-04（成纤维细胞激活蛋白抑制剂，68Ga-FAPI）PET/CT对胸部原发性非肺肿瘤进行诊断、鉴别和分期。54名参与者接受了18F-FDG和68Ga-FAPI PET/CT检查，并根据病理学结果分为良性、中间性和恶性。两个独立样本t检验比较了两种方法在原发肿瘤、淋巴结和转移灶中的最大标准摄取值（SUVmax），肿瘤与血池的比率和肿瘤与肝脏的比率。单因素方差分析用于比较18F-FDG或68Ga-FAPI的摄取在三个组之间的差异。确诊的54名参与者中有71个原发病变、56个转移淋巴结和43个转移病灶。18F-FDG PET/CT能够有效区分恶性病变和非恶性病变，准确率为87.32%（p < 0.001）。68Ga-FAPI PET/CT能够有效区分良性病变和非良性病变，准确率为91.55%（p < 0.001）。18F-FDG和68Ga-FAPI用于检测淋巴结转移的准确率分别为77.22%（61/79）和87.34%（69/79）（p = 0.096）。68Ga-FAPI在转移淋巴结中的摄取值显著高于非转移淋巴结（p < 0.001）。68Ga-FAPI PET/CT检测转移病灶的检出率显著高于18F-FDG，分别为100%（43/43）和53.49%（23/43）（p < 0.001）。与18F-FDG PET/CT相比，68Ga-FAPI PET/CT改变了7.4%（4/54）参与者的治疗策略。68Ga-FAPI PET/CT在诊断和鉴别原发性非肺肿瘤方面具有价值，对于评估淋巴结和远处转移优于18F-FDG PET/CT。使用68Ga-FAPI PET/CT检查对于原发性非肺胸部肿瘤的诊断、鉴别和探索淋巴结转移和远处转移具有重要价值。• 68Ga-FAPI PET/CT在原发性非肺肿瘤的诊断、鉴别和分期中具有价值。• 68Ga-FAPI PET/CT在评估淋巴结和远处转移方面优于18F-FDG PET/CT。©2023. 作者（作者），在欧洲放射学协会的独家许可下。

We conducted a prospective study using 18F-flurodeoxyglucose (18F-FDG) and 68Ga-DOTA-FAPI-04 (fibroblast-activation protein inhibitor, 68Ga-FAPI) PET/CT to diagnose, differentiate, and stage primary extrapulmonary tumors of the thorax.Fifty-four participants were undergoing 18F-FDG and 68Ga-FAPI PET/CT and divided into the benign, intermediate, and malignant based on pathology. The maximum standardized uptake value (SUVmax), the tumor-to-blood pool ratio, and tumor-to-liver ratio were compared for primary tumors, lymph nodes, and metastases between the two modalities by two independent samples t tests. One-way ANOVA was used to compare the uptake of 18F-FDG or 68Ga-FAPI among the three groups.Fifty-four participants were confirmed to have 71 primary lesions, 56 metastatic lymph nodes, and 43 metastatic lesions. 18F-FDG PET/CT could both effectively distinguish malignant lesions from non-malignant lesions, accuracies of 87.32% (p < 0.001). 68Ga-FAPI PET/CT effectively differentiated benign lesions from the non-benign, accuracy being 91.55% (p < 0.001). The accuracies of 18F-FDG and 68Ga-FAPI for detecting lymph node metastasis were 77.22% (61/79) and 87.34% (69/79) (p = 0.096). The uptake of 68Ga-FAPI in metastatic lymph nodes was significantly higher than that of the nonmetastatic (p < 0.001). The detection rate of 68Ga-FAPI PET/CT for metastatic lesions was significantly higher than that of 18F-FDG, 100% (43/43) vs. 53.49% (23/43) (p < 0.001). Compared with 18F-FDG PET/CT, 68Ga-FAPI PET/CT changed the treatment strategy of 7.4% (4/54) participants.68Ga-FAPI PET/CT is valuable in the diagnosis and differentiation of primary extrapulmonary tumors and superior to 18F-FDG PET/CT for evaluating lymph node and distant metastasis.The application of 68Ga-FAPI PET/CT in primary extrapulmonary chest tumors is valuable, which is reflected in diagnosis, differentiation and exploration of lymph node metastasis and distant metastasis.• 68Ga-FAPI PET/CT is valuable in the diagnosis, differentiation, and staging of primary extrapulmonary tumors. • 68Ga-FAPI PET/CT is superior to 18 F-FDG PET/CT for evaluating lymph node and distant metastasis.© 2023. The Author(s), under exclusive licence to European Society of Radiology.