Parametric features of image textures in 18F-FDG PET/CT evaluation of lung nodules / 中华核医学与分子影像杂志

ABSTRACT

Objective To evaluate the parametric features of image textures on 18F-FDG PET/CT for the differentiation between malignant and benign pulmonary nodules and compare the diagnostic performance of these parameters with SUVmax.Methods 18F-FDG PET/CT images of 170 patients (102 males,68 females,age range29-81 (mean 59)years) with pulmonary nodules were retrospectively evaluated.Eightynine pulmonary nodules (230 slices) were malignant and 81 (193 slices) were benign.The pulmonary nodules were contoured on CT images and mapped to the co-registered PET images.Thirteen parameters of textural features were extracted and SUVmax was measured.Logistic regression analysis was used to identify the significant texture parameters and create a regression model.The efficacy of the textural features and SUVmax to distinguish between malignant and benign pulmonary nodules was evaluated by ROC curve analysis.The textural features of squamous cell carcinoma and adenocarcinoma were compared via the Mann-Whitney u test.The sensitivity and specificity of the textural features and SUVmax for the differential diagnosis were compared with x2 test.Results Logistic regression model identified 4 textural features (skewness (β =1.7058),kurtosis (β =-1.0989),angular second moment (ASM,3 =-4.4140) and strength (β =0.5626) ; all P ＜ 0.05) to have significant correlation with the malignancy of lung nodules.The AUC of ROC curve was 0.775 (95％ CI0.732-0.819; P＜0.001) with the sensitivity of 89.6％ (206/230) and specificity of 50.8％ (98/193).ASM and strength had statistically significant differences between squamous cell carcinoma and adenocarcinoma [ASM0.0303 (95％ CI 0.0392-0.0724) vs 0.0594 (95％ CI 0.0721-0.0947) ; strength2.4714 (95％ CI 2.4632-4.1050) vs 1.5945 (95％ CI 1.9003-2.4652) ; u =3082.0 and 3115.0,both P＜0.01].The AUC of SUVmax-based diagnosis was 0.757 (95％ CI 0.711-0.802 ; P ＜ 0.001) with the sensitivity of 80.9 ％ (186/230) and specificity of 50.3 ％ (97/193) at a cut-off value of 2.5.The sensitivity of the textural features was superior to SUVmax in differentiating malignant from benign pulmonary nodules (x2 =6.903,P ＜ 0.01).Conclusions Image textural parametric features extracted from 18 F-FDG PET/CT are more sensitive to differentiate between malignant and benign pulmonary nodules compared to SUVmax.They might also be useful to discriminate between different pathological types of lung cancers.