18F-FDG PET/CT显像中肺外病变对肺癌的辅助定性诊断价值

背景与目的 ¹⁸F-脱氧葡萄糖（fluorodeoxyglucose,FDG）正电子发射体层摄影术/计算机体层摄影术（positron emission tomography/computed tomography,PET/CT）对肺癌和部分肺良性病变的鉴别诊断仍有一定困难,本研究旨在探讨PET/CT显像中肺外病变对肺癌的辅助定性诊断价值。方法回顾性分析126例行PET/CT检查的疑诊肺癌病例。初始诊断仅根据肺内病变的PET表现、平均标准摄取值（mean standardized uptake value,SUVmean）和CT征象,然后根据肺外病变情况对肺内病变的诊断进行修正,比较修正前后诊断结果有无差异。结果 PET/CT发现81例同时伴有肺外病变,肺外转移性病变使13例可疑恶性修正为肯定恶性,1例良性修正为肯定恶性;肺外非转移性病变使2例可疑恶性修正为肯定恶性,1例可疑恶性修正为良性。除2例全身结核被错误修正为恶性外,其它15例经病理证实均为正确修正。修正前后PET/CT的诊断结果差异有统计学意义,修正诊断率为13.5%（17/126）,修正诊断正确率为88.2%（15/17）。结论肺外病变的发现对肺癌的术前定性有着较好的实用价值,提高了诊断效能,但仍然要注意与全身多发结核等炎性病变鉴别。

The Value of Extra-lung Lesions on 18F-FDG PET/CT in Improving Diagnosis of Lung Cancer

Background and objective F-FDG PET/CT has several shortcomings in discriminating between lung carcinoma and pulmonary benign lesions.The aims of the present study is to explore the value of extra-lung lesions on F-FDG PET/CT image in the diagnosis of lung cancer.Methods A total of 126 suspected lung cancer patients underwent F-FDG PET/CT scan.Preliminary diagnoses were based on the PET characteristics,SUVmean value,and CT characteristics of the lesions in the lung,and the diagnoses were modified based on the detected extra-lung lesions.The difference between the two methods and their disparity were calculated.Results Extra-lung lesions were identified on the PET/CT image in 81 patients; extra-lung metastasis modified 13 probable malignancies to affirmative malignancy and 1 probable malignancy to benign lesion. Non-metastasis modified 2 probable malignancies to affirmative malignancy and 1 probable malignancy to benign lesion. Fifteen were correct,whereas 2 were misdiagnosed.The diagnoses modification rate was 13.5%(17/126),and the modified diagnoses accuracy is 88.2%(15/17).Conclusion Extra-lung lesions demonstrated on F-FDG PET/CT improved the diagnostic accuracy of lung cancer.Tuberculosis was identified as the most important reason for false positive diagnoses after modification by extra-lung lesions.