实性肺癌能谱CT参数与Ki-67表达水平的相关性研究

目的探讨实性肺癌能谱CT定量参数与Ki-67表达水平之间的关系。方法回顾性分析了152例经手术或活检证实的实性肺癌患者的临床资料。采用免疫组织化学检测Ki-67阳性癌细胞百分率(Ki-67值),反映Ki-67表达水平。根据Ki-67值分为3组:高水平组(大于30%),中水平组(10%~30%),低水平组(小于等于10/%)。用GSI Viewer软件测量和计算增强胸部能谱CT(静脉期)的定量参数,包括碘浓度(IC)、40和70 keV的CT值(CT40keV、CT70keV)、能谱衰减曲线的斜率(K)和标准碘浓度(NIC)。用单因素方差分析比较3组间能谱参数的差异。计算定量参数与Ki-67表达水平之间的Spearman相关系数。应用受试者工作特征曲线(ROC)分析,计算曲线下面积(AUC)、敏感度、特异度来衡量各参数的诊断性能。结果单因素方差分析显示3组间各定量参数均有显著差异(P<0.05)。LSD-t两两比较分析显示,高水平组分别与低水平组、中表达组间的IC、NIC、CT40keV、CT70keV、K有显著差异(P<0.05)。各定量参数与Ki-67表达水平呈负相关(|r|均<0.45,P<0.001)。ROC曲线分析表明,IC和K在鉴别高水平组和非高水平组方面表现最好(AUC分别为0.745和0.746)。IC和K的敏感度均为69.4%,特异度74.4%。结论能谱CT定量参数(IC、NIC、CT40keV、CT70keV、K)可用于鉴别实性肺癌Ki-67高表达与非高表达水平,并与Ki-67表达水平呈负相关,为评估实性肺癌癌细胞增殖能力提供了参考。

Association between quantitative parameters of spectral CT and Ki-67 expression levels in patients with solid lung cancer

Objective To investigate the relationship between the quantitative parameters of spectral CT and expression of Ki-67 in patients with solid lung cancer.Methods One hundred and fifty-two patients with histologically confirmed solid lung cancer were enrolled in this retrospective study.The expression level of Ki-67 was determined as the percentage of Ki-67 positive cancer cells detected by immunohistochemistry.According to the Ki-67 value,the patients were divided into 3 groups of high(>30%),medium(10%-30%),and low(≤10%)levels.The quantitative parameters of enhanced chest spectral CT in the venous phase including iodine concentration(IC),CT values at 40 keV(CT40keV)and 70 keV(CT70keV),slope of energy spectrum attenuation curve(K),and normalized iodine concentration(NIC)were measured and calculated by GSI Viewer software.One-way ANOVA was used to compare the difference between the groups.The Spearman correlation coefficients between quantitative parameters and Ki-67 expression level were calculated.Receiver operating characteristic(ROC)curve analysis using the area under the curve(AUC),sensitivity,and specificity was performed to determine the diagnostic performance of parameters.Results One-way ANOVA showed significant differences in all quantitative parameters among 3 groups(P<0.05).LSD-t pairwise comparative analysis showed significant differences(P<0.05)between high and low levels as well as high and middle levels in IC,NIC,CT40keV,CT70keV and K.Parameters were negatively correlated with the expression level of Ki-67(|r|<0.45 for all parameters,P<0.001).ROC curve analysis showed that IC and K performed the best in distinguishing high and non-high levels(AUC=0.739 and 0.740,respectively)with 68.5%sensitivity and 74.6%specificity.Conclusion Spectral CT quantitative parameters including IC,NIC,CT40keV,CT70keV,and K can distinguish the high from non-high levels of Ki-67 in solid lung cancer.The parameters have significant negative correlation with the expression level of Ki-67 and can help to evaluate the proliferation ability of solid lung cancer cells.