^18F-FDGPET/CT对孤立肺结节伴空洞鉴别诊断价值分析

目的：探讨^18F-FDG PET/CT对良恶性孤立肺结节伴空洞鉴别诊断可行性。方法：回顾性分析2009-08-06-2012-03-15华中科技大学附属协和医院50例单发肺结节伴空洞患者临床资料。根据结节CT特征和摄取FDG情况,并在PET图像中获取半定量指标最大标准摄取值（maximum Standardized uptake value,SUVmax）。分别计算CT、PET及PET/CT对病变良恶性诊断的准确性、敏感性、特异性、阳性预测值（positive predictive value,PPV）和阴性预测值（negative predictive value,NPV）,并进行χ^2检验,受试者工作特征（receiver operating characteristics,ROC）曲线进行分析。结果：50例患者中,23例证实为恶性病变,其中腺癌9例,鳞癌14例;27例为良性病变,其中肺脓肿14例,肺结核13例。CT诊断肺结节伴空洞良恶性敏感性为82.6%（19/23）,特异性为74.0%（20/27）,准确性78.0%（39/50）,PPV为73.0%（19/26）,NPV为83.3%（20/24）;PET诊断的敏感性为95.6%（22/23）,特异性为44.4%（12/27）,准确性为68.0%（34/50）,PPV为59.4%（22/37）,NPV为92.3%（12/13）;当选取SUVmax4.5为截断值时,敏感性为86.9%（20/23）,特异性为48.1%（13/27）,准确性为68.0%（34/50）,PPV为58.8%（20/34）,NPV为81.2%（13/16）;PET/CT联合诊断时敏感性为95.6%（22/23）,特异性为92.5%（25/27）,准确性为94.0%（47/50）,PPV为91.7%（22/24）,NPV为96.2%（25/26）。PET/CT对恶性和良性肺结节伴空洞诊断的准确率高于单独使用CT或PET,P〈0.01。结论：^18F-FDG PET对鉴别良恶性孤立肺结节伴空洞有较高的假阳性率,结合PET和CT形态学分析有助于提高病灶的诊断准确率。

Feasibility of ^18F-FDG PET/CT in the differential diagnosis of benign and malignant solitary pulmonary nodules with cavity

OBJECTIVE：To discuse the feasibility of ^18F-FDG PET/CT in the differential diagnosis of benign and malignant solitary pulmonary nodules with cavity.METHODS：A total of 50patients with solid pulmonary nodules with cavity were retrospectively analyzed.The data obtained from CT,PET and PET/CT was analyzed separately.The maximum standardized uptake value（SUVmax）was obtained from PET images.The accuracy,sensitivity,specificity,positive predictive value（PPV）and negative predictive value（NPV）were calculated,compared with χ^2 test and receiver operating characteristics（ROC）curve analysis were performed.RESULTS：Of the 50patients,23patients were diagnosed as malignant tumor with histopathology,in which 9patients were adenocarcinoma and 14were squamous cell carcinoma.Benign pulmonary nodules were confirmed in the other 27patients,with lung abscess（n=14）and pulmonary tuberculosis（n= 13）.The sensitivity,specificity,accuracy,PPV and NPV for CT in the diagnosis of benign and malignant lung nodules with cavity were 82.6%（19/23）,74.0%（20/27）,78.0%（39/50）,73.0%（19/26）and 83.3%（20/24）,respectively,and for PET they were 95.6%（22/23）,44.4%（12/27）,68.0%（34/50）,59.4%（22/37）and 92.3%（12/13）,respectively. When SUVmax4.5 was chosen as a cutoff,the diagnostic performance were 86.9%（20/23）,48.1%（13/27）,68.0%（34/50）,58.8%（20/34）and 81.2%（13/16）respectively.PET/CT had better diagnostic performance,and the values could reach 95.6%（22/23）,92.5%（25/27）,94.0%（47/50）,91.7%（22/24）and 96.2%（25/26）,respectively.The accuracy of PET/CT was significantly higher than that of either CT or PET alone（P0.01）.CONCLUSIONS：^18 F-FDG PET has high false positive rate in differential diagnosis of benign and malignant solitary pulmonary nodules with cavity.The combination of PET and CT,the metabolism and morphological analysis,is helpful to improve the diagnostic accuracy of the lesions.