^18F-FDG PET/CT双时相显像鉴别诊断肺良恶性病变的临床研究

[目的]探讨18F-FDGPET/CT双时相显像鉴别诊断肺良恶性病变的临床价值。[方法]65例肺病变患者（80个病灶）行18F-FDGPET/CT双时相显像,计算最大标准化摄取值SUVmax及早期、延迟显像SUVmax的变化幅度（ΔSUVmax）,并与病理及随访结果对比。利用ROC曲线计算SUVmax和ΔSUVmax诊断肺病变的最佳阈值。比较PET/CT与PET及CT的诊断效能。[结果]（1）65例共计80个肺内结节中良性结节38个,恶性结节42个。恶性结节组早期相SUVmax值为5.35（4.6）,高于良性结节组的1.75（2.0）,差异有统计学意义（Z=-4.846,P=0.0001）。恶性结节组双时相ΔSUVmax值为30.54（2.0）,高于良性结节组的16.84（2.0）,差异有统计学意义（Z=-2.861,P=0.0042）。（2）ROC分析显示早期显像SUVmax值〉2.45和双时相显像ΔSUVmax值〉24.66%是两者鉴别诊断肺良恶性结节时的最佳阈值。早期相SUVmax值〉2.45诊断肺恶性病变的灵敏度、特异性、准确率、阳性预测值和阴性预测值分别为88.10%、63.16%、76.25%、72.55%、82.76%,双时相ΔSUVmax值〉24.66%时,分别为64.29%、71.05%、67.50%、71.05%、64.29%。（3）PET/CT诊断肺病变的准确率优于PET和CT（P〈0.05）,诊断灵敏度优于CT（P〈0.05）。[结论]18F-FDGPET/CT诊断肺恶性病变,早期相SUVmax值及双时相ΔSUVmax值的最佳阈值为〉2.45和〉24.66%;并需结合病灶CT形态学特征及临床病史进行综合诊断。

Clinical Study of Dual Phase 18F-FDG PET/CT Imaging in Differential Diagnosis for Benign and Malignant Lesion of Lung

[Purpose] To investigate the clinical value of dual phase 18F-FDG PET/CT imaging in differen-tial diagnosis for benign and malignant lesion of lung. [Methods] Sixty-five cases with lung lesion (80 pulmonary nodules) underwent dual phase 18F-FDG PET/CT imaging. The maximum standardized uptake value (SUVmax) of early and delay phase were calculated respectively, and the change in SUVmax (dual phase ΔSUVmax) was defined as the ratio of the increase in SUVmax between early and delay scans to the early SUVmax. The final diagnosis were confirmed by pathological or clinical follow-up results. The diagnostic threshold of SUVmax, ΔSUVmax for lung lesion was evaluated by ROC curve. The diagnostic value between PET/CT and PET or CT was compared. [Results] (1)80 pulmonary nodules include 38 benign nodules and 42 malignant nodules. The early SUVmax of malignant nodule group was 5.35 (4.6), higher than the that of benign group 1.75(2.0) (Z=-4.846,P=0.0001). The dual phase ΔSUVmax of malignant nodule group was 30.54 (2.0), which was higher than that of the benign group 16.84(2.0) (Z=-2.861,P=0.0042). (2) ROC analysis showed that the best cutoff value of early SUVmax and dual phase SUVmax in diagnosing pulmonary nodules was>2.45 and >24.66% respectively. When early SUVmax>2.45, the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value in differential diagnosis for lung lesion was 88.10%, 63.16%, 76.25%, 72.55% and 82.76%, and when ΔSUVmax>24.66%, the value was 64.29%, 71.05%, 67.50%, 71.05% and 64.29% respectively. (3) The accuracy of PET/CT diagnosed lung lesion was higher than that of PET and CT (P<0.05), and the sensitivity was higher than CT (P<0.05). [Conclusions] The best cutoff value of early SUVmax and dual phase SUVmax is >2.45 and >24.66% respectively in 18F-FDG PET/CT diagnosis of lung lesion; and these combined with CT imaging be much better.