18F-FDG PET/CT半定量参数在肾上腺病灶鉴别诊断中的价值

The Value of Semi-quantitative Parameters of 18F-FDG PET/CT in the Differential Diagnosis of Adrenal Lesions

[目的]探讨18F-FDG PET/CT半定量参数在鉴别肾上腺病灶中的价值。[方法]对90例疑有肾上腺疾病患者的18F-FDG PET/CT检查结果进行分析。利用半定量分析法,测量所有病灶的T/L SUVmax、SUVmax、肿瘤直径和平均CT值,与最终病理结果比较。[结果]共检出110个病灶,其中恶性肾上腺病灶51例、良性肾上腺病灶39例。恶性肾上腺病灶的平均T/L SUVmax(2.9±1.6)、SUVmax(8.3±5.1)、肿瘤直径(3.1cm±1.6cm)和平均CT值(31.9±7.0Hu)较良性病灶的平均T/L SUVmax(0.9±0.5)、SUVmax(2.7±1.4)、肿瘤直径(2.1cm±1.7cm)和平均CT值(12.1±17.5Hu)显著升高(P均<0.001)。假阳性3例、假阴性2例。ROC曲线分析显示,T/L SUVmax>1.15、SUVmax>3.86、CT值>23.5Hu和肿瘤直径>2.35cm可作为鉴别良恶性肾上腺病灶的最佳截断值。此最佳截断值的ROC曲线下的面积分别为0.95、0.95、0.84和0.76。多变量Logistic回归分析表明T/L SUVmax、SUVmax可作为恶性肾上腺病灶的独立诊断因素(P<0.001)。[结论]当T/L SUVmax>1.15、SUVmax>3.86时,18F-FDG PET/CT在鉴别肾上腺病灶性质中具有较高价值。T/L SUVmax、SUVmax均可作为预测恶性病灶的独立因素,且T/L SUVmax更为客观。

[Objective]To evaluate the value of semi-quantitative parameters of 18F-FDG PET/CT for the differentiation of malignant from benign adrenal lesions.[Methods]Included 90 patients(58 men and 32 women,age 60.1±11.6 year)who had undergone 18F-FDG PET/CT for evaluation of110 adrenal lesions.For semi-quantitative analysis,adrenal to liver(T/L)SUVmaxratio,the maximum standardized uptake value(SUVmax),tumor diameter and mean CT attenuation value were measured in all lesions and compared with the pathological findings.[Results]A total of 110 lesions were detected,including 51 malignant and 39 benign.Malignant adrenal masses had a significantly higher T/L SUVmaxratio(2.9±1.6 vs.0.9±0.5),a higher mean SUVmax(8.3±5.1 vs.2.7±1.4),a greater tumor diameter(3.1±1.6 cm vs.2.1±1.7 cm)and a higher mean CT attenuation value(31.9±7.0 Hu vs.12.1±17.5 Hu)than benign lesions(P<0.001).There were three false positives and two false negatives.Based on ROC curve analysis,a T/L SUVmaxratio>1.15,an adrenal SUVmax>3.86,an attenuation value>23.5 Hu and a tumor diameter>2.35 cm were chosen as the optimal cut-off values for differentiating malignant from benign adrenal masses.The areas under the ROC curves for the selected cut-off values were 0.95,0.95,0.84 and 0.76,respectively.A multivariate logistic regression model revealed that the T/L SUVmaxand SUVmaxwere an independent prognostic factor for malignancy(P<0.001);a CT attenuation value of>23.5 Hu and a tumor diameter>2.35 cm had no additional individual importance in the diagnosis of malignancy.[Conclusion]Using a T/L SUVmax ratio>1.15 and an adrenal SUVmax>3.86 in 18F-FDG PET/CT led to high diagnostic sensitivity,accuracy and positive predictive value for characterizing adrenal lesions.T/L SUVmaxand SUVmaxcould be used as independent predictors of malignancy,however,the T/L SUVmaxis more objective.