^(18)F-FDG PET对肺癌的诊断及鉴别诊断

The clinical value of FDG PET in the diagnosis and differential diagnosis of lung cancer

目的 探讨1 8F 脱氧葡萄糖 (FDG)PET显像对肺癌诊断、鉴别诊断的临床价值。方法181例患者分为肺癌组和肺部良恶性病变鉴别组 ,均行1 8F FDGPET显像。分析病灶的标准摄取值(SUV)及其形态学表现。结果 ①肺癌组 79例 ,有 78例可见1 8F FDG浓聚 ,SUV =4.19± 1.66,其中 9例SUV <2 .5 ,6例SUV <2 .0。 93 .6%病灶表现为结节状或团块状 ,7例病灶内有放射性缺损者 ,缺损影周围组织多数浓聚程度高且较厚 ,3 5例病灶边缘呈分叶状。②肺部良恶性病变鉴别组 10 2例 ,其中确诊为肺癌的 60例患者病灶均表现为1 8F FDG高摄取 ,SUV为 4.5 7± 1.73 ;形态学表现与肺癌组一致。确诊为良性病变的 42例患者 ,病灶多表现为放射性浓聚程度低或不显影 ,SUV为 1.5 1± 1.0 5 ,与肺癌组比较差异有显著性 (P <0 .0 1)。形态学表现多样化。 6例SUV >2 .5良性病变中 ,有 2例呈片状和斑片状 ,与肺癌病灶形态有一定差异。 10 2例患者中采用SUV >2 .5、SUV >2 .5结合形态分析和SUV >2 .0结合形态分析用于诊断肺癌 ,灵敏度、特异性及准确性相近 ,后 2种方法诊断效能稍高于单用SUV >2 .5法 ,但差异无显著性 (P >0 .0 5 )。结论 1 8F FDGPET显像对肺癌诊断及鉴别诊断有较好的诊断效能。

Objective To review the morphologic characteristics and standardized uptake value (SUV) distribution of the lesions in the lung of 181 patients, and to evaluate the clinical value of FDG PET in the diagnosis and differential diagnosis of lung cancer. Methods One hundred and eighty-one patients were divided into 2 groups: the group of proved lung cancer and the group of lesions without final diagnosis. FDG PET scan was performed on all the patients. Morphologic characteristics and SUV of all lesions were analysed retrospectively. Results ①In the group of lung cancer, hypermetabolic lesions were found in 78 patients. The average SUV of the lung cancer was 4.19±1.66. Among them, the SUV was less than 2.5 in 9 cases and less than 2.0 in 6 cases. The sizes of lesions were smaller than 1.0 cm in 4 patients whose SUV<2.5. 93.6% of lesions displayed as nodules or masses. The defective zones were seen in 7 lesions and which were surrounded with thick and intense uptake margins. The margin was irregular in the largest masses(≥3 cm). ②In the group of lesions without final diagnosis, lung cancer was proved in 60 patients and benign lesions were diagnosed finally in 42 cases in this study. All lesions of lung cancer showed intense uptake of 18F-FDG. The SUV of the malignancy was 4.57±1.73. The morphologic characteristics of these malignancies were similar as that of the group of proved lung cancer. In the benign lesions, most of them had no, or mild uptake of 18F-FDG. The SUV of them were less significant than that in malignant lesions(1.51±1.05 vs 4.57±1.73,P<0.01). The shapes of benign lesions were various. Among 42 benign lesions, the SUV was higher than 2.5 in 6 cases. The shape of 2 of them displayed as sheet or patch and were different to that of malignant lesions. Three indexes which were SUV>2.5,SUV>2.5 combining with morphological findings and SUV>2.0 combining with morphological findings, were selected for differential diagnosis. The sensitivity, specificity and accuracy of these three indexes for diagnosis of lung cancer were all about 90%. The diagnostic efficiency of the latter 2 was slightly higher than that of the first one but the difference was not significant (P>0.05). Conclusions 18F-FDG PET is an excellent modality in the diagnosis and differential diagnosis of lung cancer. The SUV and morphology are significantly different between the malignant and most of the benign lesions. The SUV combining with morphological findings sometimes may be helpful for the differential diagnosis.