PET标准化摄取值在肺癌诊断中的价值及其影响因素的探讨

Diagnostic value and analysis of the influencing factors for SUV in lung cancer

评价了标准化摄取值(Standard uptake values,SUVs)在肺内病灶鉴别诊断中的价值,并寻找其最佳诊断界值;探讨了肺癌病灶SUV值的影响因素。回顾性分析接受PET-CT检查的、有肺部病灶的患者84例(合计59个恶性病灶,30个良性病灶)。通过感兴趣区(Region ofinterest,ROI)技术勾画肺内病灶,记录每个肺内病灶最大SUV(SUVmax)和平均SUV(SUVave);通过ROC曲线统计方法比较SUVmax和SUVave的诊断效率,并明确最佳诊断界值。通过相关性分析和协方差分析等统计方法研究肺癌病灶SUVave和肿瘤病理类型、瘤灶大小的关系。SUVmax的ROC曲线下面积为0．8975,SUVave的ROC曲线下面积为0．8966,两者在鉴别肺内病灶良恶性中无统计学差异(P>0.05)。以SUVmax为5.2和SUVave为4.4时,其诊断敏感度、特异度、准确率均为89.8%、80.0%和86.5%,其准确率最高。鳞癌组SUV和瘤灶大小分别为8.5±2.9、4.1±1.5 cm,均显著大于腺癌组的SUV(5.3±2.2)和瘤灶大小(2.5±1.0 cm)(P<0.05)。在所有恶性病灶及分别在鳞癌、腺癌组中,病灶SUV均与大小呈明显正相关(P<0.05)。协方差分析比较修正瘤灶大小后,鳞癌SUV(7.2±o.5)大于腺癌(6.1±0.4),但无统计学差异(P>0.05)。SUV在肺内病灶良恶性鉴别中有较高的诊断价值;在本组病例中,以SUVmax、SUVave分别为5.2、4.4时,其诊断效率最高;肺癌病灶的SUV受瘤灶大小因素影响显著,鳞癌组与腺癌组的SUV无显著统计学差异。

To assess the diagnostic value of standard uptake values （SUVs） in lung lesions and to explore the optimal threshold, the biological influencing factors for SUV in lung cancer were researched. 84 patients, all of whom had lung lesions, experienced PET-CT scanning （malignant lesions 59, benign lesions 30, respectively）. Every lung lesion was measured by the technique of region of interest （ROI）, and each lesion＇s maximal SUV（SUVmax） and average SUV（SUVave） values were recorded. The diagnostic efficiencies of SUVmax and SUVave were compared and the optimal threshold was established according to the analysis of the ROC curve. The relationships between SUVave and pathologic type and tumor size were analyzed through the analysis of correlation and variance with covariates. There is no significant difference between the areas under curves of SUVmax （0.8975） and SUVave （0.8966）, so the diagnostic values of these two methods for lung lesions are similar. When SUVmax〉5.2 or SUVave〉4.4 was taken as the cut-off value, the diagnostic accuracy was the highest, and the sensitivity, specificity and accuracy is 89.8%, 80.0%, 86.5%, respectively. Squamous cell carcinoma had higher SUV （8.5＋9.9） and bigger tumor size （4.1＋1.5 cm） than adenocarcinoma （5.3±2.2, 2.5±1.0 cm） （P〈0.05）. There is a significant positive correlation between tumor size and SUV either in squamous cell carcinoma or in adenocarcinoma （P〈0.05）. After eliminating the influence of tumor size, SUV of squamous cell carcinoma （7.2±0.5） is still higher than that of adenocarcinoma （6.1±0.4）, but there is no statistic significance （P〉0.05）. It is concluded that SUV is useful for differentiating lung lesions. When SUVmax〉5.2 or SUVave〉4.4 is taken as the cut-off value, the diagnostic accuracy is highest. The SUV of lung cancer is more likely influenced by tumor size than by pathologic type.