From the Department of Radiation Oncology, Shandong University Cancer Center, Jinan, China (Y.W., S. Yuan, J.Y.); Department of Radiation Oncology and Shandong Provincial Key Laboratory of Radiation Oncology (Y.W., J.L., S. Yuan, J.Y.) and Department of Nuclear Medicine PET Center, Shandong Cancer Hospital and Institute (L.M., J.R., S. Yan, H.W., Z.F.), Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, No. 440 Jiyan Rd, Jinan 250117, China; and Research Unit of Radiation Oncology, Chinese Academy of Medical Sciences, Jinan, China (Y.W., P.L., J.Y.).
Radiology. 2023 Aug;308(2):e222785. doi: 10.1148/radiol.222785.
Background The radiotracer fluorine 18 (F)-labeled fibroblast activation protein inhibitor (FAPI) has shown promise for visualizing several types of cancer, but the accuracy of F-FAPI compared with F-fluorodeoxyglucose (FDG) for the detection of lung cancer remains uncertain. Purpose To evaluate the effectiveness of F-FAPI-based PET/CT imaging for the diagnosis of primary and metastatic lung cancer lesions as compared with F-FDG PET/CT. Materials and Methods In this secondary analysis of a prospective trial, consecutively recruited patients from a single center with pathologically confirmed lung cancer were prospectively enrolled from December 2020 to April 2022 and underwent paired F-FAPI and F-FDG PET/CT examinations at intervals of more than 20 hours and within 7 days of each other. Histopathologic and clinical follow-up results were used as reference standards for final diagnoses. F-FAPI and F-FDG uptake were compared using the McNemar test or paired Student test. Diagnostic accuracy was compared between the two techniques by using the McNemar χ test. Results Sixty-eight participants (median age, 63 years [IQR, 58-68 years; range, 42-79 years]; 46 male [68%]) were evaluated. Compared with the mean tumor-to-background ratio (TBR) for FDG uptake, TBR for FAPI uptake was lower in primary lung tumors (25.3 ± 14.0 [SD] vs 32.1 ± 21.1; < .001) but higher in metastatic lymph nodes (7.5 ± 6.6 vs 5.9 ± 8.6; < .001) and bone metastases (8.6 ± 5.4 vs 4.3 ± 2.3; < .001). For diagnostic accuracy in a total of 548 lesions in 68 participants, compared with F-FDG PET/CT, F-FAPI PET/CT demonstrated a higher sensitivity (99% [392 of 397 lesions] vs 87% [346 of 397]; < .001), specificity (93% [141 of 151 lesions] vs 79% [120 of 151]; = .004), accuracy (97% [533 of 548 lesions] vs 85% [466 of 548]; < .001), and negative predictive value (97% [141 of 146 lesions] vs 70% [120 of 171 lesions]; < .001), but there was no evidence of a difference for positive predictive value (98% [392 of 402 lesions] vs 92% [346 of 377 lesions]; = .57). Conclusion F-FAPI PET/CT may be superior to F-FDG PET/CT for detecting lung cancer. © RSNA, 2023 See also the editorial by Zukotynski and Gerbaudo in this issue.
背景 放射性示踪剂氟 18（F）标记的成纤维细胞激活蛋白抑制剂（FAPI）已显示出在可视化多种类型的癌症方面的潜力，但 F-FAPI 与 F-氟脱氧葡萄糖（FDG）在检测肺癌方面的准确性仍不确定。目的 评估 F-FAPI 基于 PET/CT 成像在诊断原发性和转移性肺癌病变方面的有效性，与 F-FDG PET/CT 进行比较。材料与方法 在这项前瞻性试验的二次分析中，2020 年 12 月至 2022 年 4 月期间，来自一家单中心的经病理证实患有肺癌的连续招募患者前瞻性入组，并在间隔超过 20 小时且彼此之间不超过 7 天的时间内接受 F-FAPI 和 F-FDG PET/CT 检查。组织病理学和临床随访结果被用作最终诊断的参考标准。使用 McNemar 检验或配对学生 t 检验比较 F-FAPI 和 F-FDG 的摄取。使用 McNemar χ 检验比较两种技术之间的诊断准确性。结果 68 名参与者（中位年龄，63 岁[IQR，58-68 岁；范围，42-79 岁]；46 名男性[68%]）接受了评估。与 FDG 摄取的平均肿瘤与背景比（TBR）相比，原发性肺癌肿瘤的 FAPI 摄取 TBR 较低（25.3 ± 14.0[SD]与 32.1 ± 21.1；<.001），但转移性淋巴结（7.5 ± 6.6 与 5.9 ± 8.6；<.001）和骨转移（8.6 ± 5.4 与 4.3 ± 2.3；<.001）较高。在总共 68 名参与者的 548 个病变的诊断准确性方面，与 F-FDG PET/CT 相比，F-FAPI PET/CT 表现出更高的灵敏度（99%[397 个病变中的 392 个]与 87%[397 个病变中的 346 个]；<.001）、特异性（93%[151 个病变中的 141 个]与 79%[151 个病变中的 120 个]；=.004）、准确性（97%[548 个病变中的 533 个]与 85%[548 个病变中的 466 个]；<.001）和阴性预测值（97%[146 个病变中的 141 个]与 70%[171 个病变中的 120 个]；<.001），但阳性预测值没有证据表明存在差异（98%[402 个病变中的 392 个]与 92%[377 个病变中的 346 个]；=.57）。结论 F-FAPI PET/CT 可能优于 F-FDG PET/CT 用于检测肺癌。 ©RSNA，2023 请参阅本期 Zukotynski 和 Gerbaudo 的社论。
