METHODS: In this prospective pilot study, we enrolled patients scheduled for surgical resection of NSCLC based on specific criteria designed to align with indications for invasive staging procedures. Patients were included when meeting at least one of the following: (1) presence of FDG-positive N2 lymph nodes, (2) clinical N1 stage, (3) central tumor location or tumor diameter of ≥ 3 cm, and (4) adenocarcinoma exhibiting high FDG uptake. [68Ga]FAPI-46 PET/CT was performed before surgery after a staging workup including [18F]FDG PET/CT. The diagnostic accuracy of [68Ga]FAPI-46 PET/CT for \"N2\" nodes was assessed through per-patient visual assessment and per-station quantitative analysis using histopathologic results as reference standards.
RESULTS: Twenty-three patients with 75 nodal stations were analyzed. Histopathologic examination confirmed that nine patients (39.1%) were N2-positive. In per-patient assessment, [68Ga]FAPI-46 PET/CT successfully identified metastasis in eight patients (sensitivity 0.89 (0.52-1.00)), upstaging three patients compared to [18F]FDG PET/CT. [18F]FDG PET/CT detected FDG-avid nodes in six (42.8%) of 14 N2-negative patients. Among them, five were considered non-metastatic based on calcification and distribution pattern, and one was considered metastatic. In contrast, [68Ga]FAPI-46 PET/CT correctly identified all non-metastatic patients solely based on tracer avidity. In per-station analysis, [68Ga]FAPI-46 PET/CT discriminated metastasis more effectively compared to [18F]FDG PET/CT-based (AUC of ROC curve 0.96 (0.88-0.99) vs. 0.68 (0.56-0.78), P < 0.001).
CONCLUSIONS: [68Ga]FAPI-46 PET/CT holds promise as an imaging tool for preoperative mediastinal nodal staging in NSCLC, with improved sensitivity and the potential to reduce false-positive results, optimizing the need for invasive staging procedures.
方法:在这项前瞻性试点研究中,我们根据旨在与侵入性分期程序的适应症相一致的特定标准,纳入了计划进行NSCLC手术切除的患者.当满足以下至少一项时,患者被纳入:(1)FDG阳性N2淋巴结的存在,(2)临床N1期,(3)中央肿瘤部位或肿瘤直径≥3cm,和(4)表现出高FDG摄取的腺癌。[68Ga]FAPI-46PET/CT在手术前进行分期检查,包括[18F]FDGPET/CT。[68Ga]FAPI-46PET/CT对“N2”淋巴结的诊断准确性是通过每位患者的视觉评估和以组织病理学结果为参考标准的每站定量分析来评估的。
结果:分析了23例75个节点的患者。组织病理学检查证实9例(39.1%)为N2阳性。在每位患者的评估中,[68Ga]FAPI-46PET/CT成功识别8例患者的转移(敏感性0.89(0.52-1.00)),与[18F]FDGPET/CT相比,3例患者的分期更高。[18F]FDGPET/CT在14例N2阴性患者中的6例(42.8%)中检测到FDG阳性淋巴结。其中,根据钙化和分布模式,五个被认为是非转移性的,一个被认为是转移性的。相比之下,[68Ga]FAPI-46PET/CT仅基于示踪剂亲和力正确识别所有非转移性患者。在每站分析中,与基于[18F]FDG的PET/CT相比,[68Ga]FAPI-46PET/CT更有效地区分转移(ROC曲线的AUC0.96(0.88-0.99)vs.0.68(0.56-0.78),P<0.001)。
结论:[68Ga]FAPI-46PET/CT有望作为非小细胞肺癌术前纵隔淋巴结分期的成像工具,具有提高的灵敏度和减少假阳性结果的潜力,优化侵入性分期程序的需求。