Extrapulmonary benign and malignant lesions avid for 18F-fluoro-deoxyglucose by multivariate regression model identification

Whether extrapulmonary lesions are avid for18F-fluorodeoxyglucose(18F-FDG) could help to differentiate the benign or malignant lung lesions.In this trial,the 199 consecutive patients with newly diagnosed lung lesions(169 malignant and 36 benign lesions) were imaged by whole body18F-FDG PET/CT.Histopathology and clinic results served as the reference standard.The malignancy likelihood were conducted by CTscores;the maximum standardized uptake value(SUVmax) of lung lesions,and PET on FDG negative or positive,as well as metastasis index(MI),by PET combined with CT findings.The data were analyzed by stepwise logistic regression and receiver-operatingcharacteristic.The malignancy predictive probability(P) was obtained by P =ex/(1+ex),where x= –1.16+0.87(CTscore) +0.15(SUVmax)+0.27(MI).The area under curve(AUC) for the fitted logistic model was 0.82±0.04,this was superior and significantly different from SUVmax(AUC,0.73±0.05) and CTscores(AUC,0.71±0.05).The fitted logistic model could improve the diagnostic performance.The MI could help for differential diagnosis.