18F-FDG PET/CT双时相显像对肺部病灶的定性诊断价值

Objective The aim of this study was to evaluate the value of dual-time point 18F-fluorodeoxyglucose (FDG) PET imaging for the differentiation between pulmonary malignant and benign lesions.Methods Seventy-eight patients with clinically suspected lung cancer underwent dual-time point 18F-FDG PET imaging.The maximum standardized uptake value(SUVmax)was calculated for PET imaging of both time points,and the change in SUVmax(△SUV)was defined as the ratio of the increase in SUVmax between early and delayed scans to the SUVmax in the early scan.The final diagnoses were confirmed by histopathology,bacteriology or clinical follow-up.The t-test was used to compare SUVmax,△SUV of benign and malignant groups.The receiver operating characteristic(ROC)curve was used to evaluate the diagnostic value of SUVmax and △SUV for pulmonary lesions.Results (1)There were 60/78 patients with pulmonary malignant lesions and 18/72 patients with benign lesions including 16 with hyperplasia lesions.There was significant difference in the SUVmax between early scan and delayed scan in both malignant group(7.94±4.17 and 9.92±5.33,respectively,t=10.19,P＜0.01)and benign group(7.21±5.74 and 8.54±6.61,respectively,t=8.23,P＜0.01).There was no significant difference in the SUVmax between malignant group and benign group in both early scan(t=0.60,P＞0.05)and delayed scan(t=0.91,P＞0.05).The △SUV was not significantly difierent between malignant and benigh groups [(26.04± 14.73)%and(18.09±24.09)%,respectively,t=1.67,P＞0.05].The SUVmax decreased in only 2 of 18 benign lesions,and no SUVmax decrease in all of the malignant lesions.(2)The sensitivity,specificity,accuracy,positive predictive value and negative predictive value with a threshold of SUVmax ＞2.5 and △SUV＞20%were respectively 93.33%(56/60),22.22%(4/18),76.92%(60/78),80.00%(56/70)and 50.00%(4/8);and 63.33%(38/60),50.00%(9/18),60.26%(47/78),80.85%(38/47)and 70.97%(22/31).The areas under the ROC curves were 0.61(Z=1.38,P＞0.05)and 0.56(Z=0.65,P＞0.05)according to the SUVmax and △SUV respectively,and the difference was not statistically significant.Condusiom Dual-time point 18F-FDG PET imasing is not useful for differentiating pulmonary malignancy from the benign lesions of hyperplasia.However,if SUVmax decreases on delayed scan,the lesion is more likely to be benign.

The value of dual-time point 18F-FDG PET imaging for the differentiation between pulmonary malignant and benign lesions