Objective To investigate the causes of false-positive results in the 68Ga-labeled fibroblast activation protein inhibitor (68Ga-FAPI-04) PET/CT imaging. Methods The imaging data of 547 patients undergoing 68Ga-FAPI-04 PET/CT examination in the Department of Nuclear Medicine of the Affiliated Hospital of Southwest Medical University from September 2020 to May 2021 were retrospectively collected.Two experienced nuclear medicine diagnostic physicians analyzed the clinical data,relevant imaging examinations,laboratory examinations,pathological results and follow-up results of the patients with false-positive results. Results The 68Ga-FAPI-04 PET/CT imaging of 547 patients showed false-positive results in 99 (18.1%) patients,including 56 males and 43 females.The postoperative pathological examination confirmed false-positive results in 13 patients,including 1 patient of thyroiditis,2 patients of pulmonary tuberculosis,1 patient of bone tuberculosis,2 patients of pulmonary inflammatory pseudotumor,1 patient of pulmonary sarcoidosis,1 patient of pulmonary benign fibroma,1 patient of organic pneumonia,2 patients of renal angiomyolipoma,1 patient of mass pancreatitis,and 1 patient of pancreatic mucinous cystadenoma.The medical history,relevant imaging examination,and long-term follow-up confirmed false-positive results in 86 patients.Specifically,the false-positive uptake in the neck,chest,abdomen,bone joint,and skin occurred in 8 (9.3%),13 (15.1%),5 (5.8%),57 (66.3%),and 3 (3.5%) patients,respectively.Inflammation-related uptake appeared in 83 (83.8%) patients with false-positive imaging results,of which arthritis (23 patients) and osteophyte (29 patients) were the most common.Sixteen (16.2%) patients showed the false-positive uptake related to fibroblasts. Conclusion 68Ga-FAPI-04 PET/CT imaging will show non-malignant tumor false-positive results,which are mainly associated with inflammation and fibroblasts.
目的 探讨68Ga标记的成纤维细胞活化蛋白抑制剂(68Ga-FAPI-04)PET/CT显像出现假阳性的原因。方法 回顾性收集西南医科大学附属医院核医学科2020年9月至2021年5月547例行68Ga-FAPI-04 PET/CT检查患者的影像学资料,由2名有经验的核医学诊断医师根据患者临床资料、相关影像学检查、实验室检查、病理及随访结果对假阳性病例进行分析。结果 547例68Ga-FAPI-04 PET/CT显像中共发现假阳性99例(18.1%),其中男56例,女43例。13例经术后病理诊断,包括甲状腺炎1例、肺结核2例、骨结核1例、肺炎性假瘤2例、肺结节病1例、肺良性纤维瘤1例、机化性肺炎1例、肾血管平滑肌脂肪瘤2例、肿块型胰腺炎1例及胰腺黏液囊腺瘤1例;86例经病史、相关影像学检查及长期随访证实,其中颈部8例(9.3%)、胸部13例(15.1%)、腹部5例(5.8%)、骨关节57例(66.3%)、皮肤3例(3.5%)。假阳性显像中与炎症有关的摄取83例(83.8%),以关节炎(23例)和骨赘(29例)最多见;与成纤维细胞有关的摄取16例(16.2%)。结论 68Ga-FAPI-04 PET/CT会出现非恶性肿瘤性假阳性显像,主要与炎症及成纤维细胞有关。.
Keywords: PET/CT; false positive; fibroblast activation protein inhibitor; isotope labeling.