双能量CT多定量参数可评估卵巢高级别浆液性癌肿瘤细胞的增殖活性.pdf

Dual-energy CT multiple quantitative parameters can evaluate the proliferative activityof high-grade serous ovarian carcinomaCHEN Suyue1,2,CHEN Wang2,WANG Lihuan3,ZHAO Yi11Department of Medical Imaging,Affiliated Hospital of Yangzhou University,Yangzhou 225100,China;2Department of Medical Imaging,Yancheng No.1 Peoples Hospital,Affiliated Hospital of Medical School,Nanjing University,Yancheng 224000,China;3Department ofMedical Imaging,The First Peoples Hospital of Taicang,Taicang 215400,China摘要：目的 探讨双能量CT多定量参数无创评估卵巢高级别浆液性癌肿瘤细胞增殖能力的价值。方法 回顾性收集2021年6月2023年1月盐城市第一人民医院66例经手术证实的连续性卵巢高级别浆液性癌病例，所有患者术前2周内均行能谱CT平扫及增强扫描，术后所有肿瘤组织病理标本切片行Ki-67免疫组织化学染色，根据术后病理分为Ki-67高表达组（n=34）及Ki-67低表达组（n=32）；由2位观察者分别独立测量病灶动脉期及静脉期4090 keV单能量CT值、碘浓度，计算标准化碘浓度及能谱曲线斜率（K40-90 keV）；采用组内相关系数检验2位测量者测量参数之间相关性及一致性的程度；比较两组之间各参数的差异，对差异有统计学意义的参数采用ROC曲线分析诊断效能，并分析差异有统计学意义的参数与Ki-67表达的相关性。结果 2位测量者对动脉期、静脉期两组间测得的各参数一致性较好，组内相关系数均大于0.75；低表达组动脉期、静脉期4070 keV单能量CT值、K40-90 keV、碘浓度、标准化碘浓度均低于Ki-67高表达组（P0.05），ROC曲线分析显示动脉期K40-90 keV诊断效能最高，曲线下面积为0.913，敏感度为91.2%，特异性为87.5%，阈值为0.95，上述参数与Ki-67表达均有相关性，以动脉期K40-90 keV与其的相关系数最高（rs=-0.900，P0.001）。结论双能量CT多定量参数可无创评估卵巢高级别浆液性癌肿瘤细胞的增殖能力。关键词：卵巢高级别浆液性癌；双能量 CT；多定量参数；Ki-67Abstract:Objective To explore the value of non-invasive assessment for the proliferative ability of ovarian high-grade serouscarcinoma tumor cells using dual-energy CT multiple quantitative parameters.Methods We retrospectively analyzed 66 casesof high-grade serous ovarian carcinoma confirmed by surgery at the First Peoples Hospital of Yancheng City from June 2021 toJanuary 2023.All patients underwent spectral CT plain and enhanced scans within 2 weeks prior to surgery.After surgery,alltumor tissue pathological specimens were stained with Ki-67 immunohistochemistry.According to postoperative pathologicalfindings,patients were classified into Ki-67 high expression group(n=34)and Ki-67 low expression group(n=32).Themeasurement of arterial and venous phase single-energy CT values(40-90 keV)and iodine concentration of the lesions wereindependently conducted by two observers.Normalized iodine concentration and energy spectrum curve slope(K40-90 keV)werecalculated.Intra-group correlation coefficient was used to evaluate the consistency and correlation between the measurementparameters of the two observers.The differences in various parameters between the two groups were compared.ROC curveswere calculated to evaluate the diagnostic efficacy of the related parameters with statistically significant differences.Thecorrelation between the parameters with statistically significant differences and Ki-67 expression was analyzed.Results Twoobservers showed good consistency in the measurement of various parameters in the arterial and venous phases,with all theintra-group correlation coefficient was greater than 0.75.The low expression group had lower arterial and venous phase 40-70keV single-energy CT values,iodine concentration,normalized iodine concentration and K40-90 keVthan the high expressiongroup(P0.05).ROC curve analysis showed that the diagnostic efficacy of arterial phase K40-90 keVwas the highest,with an AUCof 0.913,sensitivity of 91.2%,specificity of 87.5%,and a threshold of 0.95.The above parameters were also correlated with Ki-67 expression,with the highest correlation coefficient observed between arterial phase K40-90keVand Ki-67(rs=-0.900,P0.05，表1）。本研究通过盐城市第一人民医院伦理委员会许可批准，伦理号：2023-(k-013)。表1 两组患者一般资料对比Tab.1 Comparison of general information between the two groups of patientsIndexAge（year,MeanSD）Occurrence site n(%)LeftRightDuplexClinical symptoms n(%)NoYesMaximum diameter of tumor（mm,MeanSD）Ki-6730%group(n=32)61.1910.666（50）6（54.5）20（46.5）16（47.1）16（50）67.2847.26Ki-6730%group(n=34)58.069.316（50）5（45.5）23（53.5）18（52.9）16（50）85.9144.722/t1.2610.2400.057-1.646P0.2120.8870.8110.1051.2 检查设备及方法所有患者均采用SOMATOM Definition Force双能CT（Siemens Healthineers）行全腹部平扫及动脉期、静脉期双能量扫描。患者取仰卧位，扫面范围自膈顶至耻骨联合下缘，采用Ulrich高压注射器经右肘静脉注射对比剂优维显(370 mgI/mL)，注射剂量为1.2 mL/kg、注射速率3.5 mL/s。采用对比剂智能跟踪技术，感兴趣区域(ROI)置于右肾门水平的腹主动脉，注射对比剂10 s分子影像学杂志,2023,46(4):661-668http:/www.j- 662后开始监测，触发阈值为100 Hu，延迟6 s启动头-足方向扫描，动脉期扫描完毕后延迟40 s采集静脉期图像。A、B球管电压分别为100 kV、Sn 150 kV，准直器宽度1280.6 mm，螺距0.6，转速0.5 s，采用自动管电流技术（CARE Dose 4D），参考管电流分别为180 mAs和90 mAs。双能量重建层厚1 mm、层间距0.7 mm，卷积核Qr40。1.3 图像后处理及分析由2位资深放射科医师（分别具备11年和19年影像诊断经验）在不知患者临床及病理结果的前提下分别测量病变。将100 kV、Sn 150 kV单能图像同时调入双能量 CT 工作站（Syngo.via VB10,Dual Energy,Sie-mens,Germany），于相应成像模式下进行数据测量。ROI需尽量避开肿块的边缘、钙化、坏死部分、各种伪影、大血管等，选择实性成分较多、强化程度最高的区域，且同一患者相同部位 ROI的大小、形状和位置尽量保持一致，再选取其上下两个层面测量，三者取平均值作为测量结果。最终将2位医师测量的数值进行一致性检验，结果较好时取其平均值作为最终数值。本研究需要测量和计算的相关数据：（1）测量动脉期、静脉期碘浓度（IC），计算标准化碘浓度（NIC），计算公式为：NIC=IC病灶/IC同层髂动/静脉；（2）测量40、50、60、70、80、90 keV单能量CT值；（3）计算动脉期、静脉期能谱曲线斜率（K），计算公式为：K=（CT40 keV-CT90 keV）/（40-90），公式中CT40 keV表示40 keV单能图上ROI对应的CT值，CT90 keV表示90 keV单能图上ROI对应的CT值。1.4 Ki-67检测方法及数据判读利用甲醛将所取标本固定、脱水，组织蜡块切片层厚为4 m，Ki-67抗体采用鼠抗人单克隆抗体，详细步骤按照相应的试剂盒进行检测。将制备好的切片于低倍镜下观察，Ki-67阳性表达的判定标准为肿瘤细胞核内呈现清晰的棕黄色或黄褐色颗粒，由病理科医师手动计算其百分比来记录Ki-67的表达水平。本研究参考相关文献将Ki-6730%定义为高表达，30%定义为低表达 4。1.5 统计学分析采用SPSS26.0统计分析软件对所采集原始数据进行分析处理；采用组内相关系数（ICC）检测2位医师测量病灶双期各参数的一致性；采用Kolmogorov-Smirov检验各计量资料是否符合正态分布，正态分布的参数以均数标准差表示，差异的比较采用独立样本t检验，非正态分布的参数以中位数（四分位间距）表示，差异的比较采用非参数检验；计数资料以n(%)表示，采用2检验，以Pgroup 30%group(n=34)Observer 1202.0364.95144.9341.85110.4029.1188.9821.3674.1116.5064.1213.261.780.3134.456.72Observer 2198.7763.52138.7341.85104.2029.1182.7821.3769.9116.5161.1213.251.590.3132.376.85ICC0.9940.9890.9780.9600.9690.9750.8340.950http:/www.j-分子影像学杂志,2023,46(4):661-668 6632.2 双能量CT各参数在两组间比较双能量CT各参数在Ki-67高、低表达组间比较，低表达组动脉期、静脉期4070 kev单能量CT值、K40-90 keV、IC、NIC均低于Ki-67高表达组，差异有统计学意义（P0.05，表45）。IndexCT40 keV(Hu)CT50 keV(Hu)CT60 keV(Hu)CT70 keV(Hu)CT80 keV(Hu)CT90 keV(Hu)K40-90 keVIC(mg/mL)NIC(%)Ki-6730%group(n=32)137.0439.84105.7324.3586.7215.3774.9310.4467.338.0162.186.931.490.761.300.2723.035.16Ki-6730%group(n=34)200.4064.17141.8341.86107.3029.1185.8821.3672.0116.5062.6213.262.751.051.690.3133.416.78t4.784.243.552.611.450.165.545.386.96P0.0010.0010.0010.0110.1510.8670.0010.00130%group(n=34)146.5255.41108.0336.4884.4125.370.2818.2861.0114.2754.5411.121.840.920.890.449.804.47t5.7665.2544.4153.4772.2160.8446.553.8903.704P0.0010.0010.0010.0010.1300.4020.0010.0010.001表4 动脉期两组患者双能量CT各参数Tab.4 Each parameter of dual-energy CT in two groups of patients in arterial phase(MeanSD)2.3 双能量CT各参数对HGSOC患者Ki-67表达的诊断效能本研究中动、静脉期双能量CT各参数中，以动脉期K40-90 keV诊断效能最高，曲线下面积(AUC)为0.913，敏感度为91.2%，特异性为87.5%，阈值为0.95（表67、图12）。表6 动脉期双能量CT各参数对 HGSOC患者Ki-67 表达诊断效能分析Tab.6 Analysis of diagnostic efficacy of various parameters of arterial phase dual-energy CT on Ki-67 expression in patientswith HGSOC.IndexCT40 keV(Hu)CT50 keV(Hu)CT60 keV(Hu)CT70 keV(Hu)K40-90 keVIC(mg/mL)NIC(%)AUC0.9030.8710.8020.7190.9130.7810.776Sensitivity(%)97.176.552.958.891.276.588.2Specificity(%)75.084.496.984.487.565.656.2Threshold90.9682.0278.7865.530.950.555.8595%CI0.829,0.9780.788,0.9550.699,0.9060.595,0.8420.838,0.9870.671,0.8900.665,0.886IndexCT40 keV(Hu)CT50 keV(Hu)CT60 keV(Hu)CT70 keV(Hu)K40-90 keVIC(mg/mL)NIC(%)AUC0.8230.7900.7340.6670.8820.8270.869Sensitivity(%)70.664.750.073.582.470.682.4Specificity(%)93.793.793.762.584.490.687.5Threshold158.49121.30101.5270.051.741.5524.8095%CI0.719,0.9260.677,0.9040.609,0.8590.533,0.8010.798,0.9620.724,0.9300.776,0.962表7 静脉期双能量CT各参数对 HGSOC患者Ki-67 表达诊断效能分析Tab.7 Analysis of the diagnostic efficacy of each parameter of intravenous phase dual-energy CT on Ki-67 expression in HG-SOC patients.分子影像学杂志,2023,46(4):661-668http:/www.j- 6642.4 双能量CT各参数与HGSOC患者Ki-67表达的Spearman相关性分析动、静脉期双能量CT各参数与Ki-67表达均有相关性，以动脉期K40-90 keV与其相关系数最高（rs=-0.900，P0.001，表8、图3）。Sensitivity1-SpecificitySource of the curveVP CT40 keVVP CT50 keVVP CT60 keVVP CT70 keVReference lineSource of the curveAP ICAP NICAP KReference lineSensitivity1-Specificity图1 动脉期双能量各参数鉴别Ki-67表达的ROC曲线Fig.1 ROC curves of each parameter of dual energy in the arterial phase to identify Ki-67 expression.Source of the curveVP ICVP NICVP KReference lineSensitivity1-SpecificitySensitivity1-SpecificitySource of the curveVP CT 40 keVVP CT 50 keVVP CT 60 keVVP CT 70 keVReference line图2 静脉期双能量各参数鉴别Ki-67表达的ROC曲线Fig.2 ROC curves of each parameter of dual energy in the intravenous phase to identify Ki-67 expression.IndexCT40 keVCT50 keVCT60 keVCT70 keVK40-90 keVICNICArterial phasers0.8900.8500.7630.6220.9000.7390.779P0.0010.0010.0010.0010.0010.0010.001Venous phasers0.6880.6030.4920.3430.7590.6830.750P0.0010.0010.0010.0010.0010.0010.001表8 动、静脉期双能量CT各参数与Ki-67表达的Spearman相关性分析Tab.8 Spearman correlation analysis between each parameter of dual energy CT and Ki-67 expres-sion in the arterial and venous phaseKi-67AP Kr=0.900,P0.001图3 动脉期K40-90 keV与Ki-67表达的相关性分析散点图Fig.3 Scatter plot of correlation analysis betweenK40-90 keVand Ki-67 expression in the arterial phase.http:/www.j-分子影像学杂志,2023,46(4):661-668 6652.5 典型病例分析典型病例影像和免疫组化分析结果显示，2例均为卵巢高级别浆液性癌，Ki-67表达分别为80%、20%。低能级图像较高能级图像软组织密度分辨率更高，对肿瘤内部结构显示更为清晰；静脉期IC及NIC均高于动脉期，Ki-67高表达者动脉期及静脉期IC及NIC均高于Ki-67低表达者；两例肿瘤能谱曲线均为下降型，静脉期K40-90 keV大于动脉期，Ki-67高表达者K40-90 keV大于Ki-67低表达者（图45）。图4 高表达组患者双能量CT参数测量结果及Ki-67表达图Fig.4 Results of dual-energy CT parameter measurements and Ki-67 expression maps ofpatients in the high expression group.Female,54 years old,HGSOC of the left side,Ki-67(80%).A-B:Mono-energy CT images(40 keV,70 keV)in arterial phase;D,E:Mono-energy CT images(40 keV,70 keV)in venous phase;C,F:Iodine density in arterial andvenous phases;G,H:Energy spectrum curve in arterial and venous phases;I:Microscopic yellowish staining of tumor cell nuclei(SP,1020),Ki-67(80%).ABCDEFGHIG图5 低表达组患者双能量CT参数测量结果及Ki-67表达图Fig.5 Dual-energy CT parameter measurements and Ki-67 expression maps of patientsin the low expression group.Female,54 years old,HGSOC of the right side,Ki-67（20%）.A,B:Mono-energy CT images(40 keV,70 keV)in arterial phase;D,E:Mono-en-ergy CT images(40 keV,70 keV)in venous phase;C,F:Iodine density in arterial and ve-nous phases;G,H:Energy spectrum curve in arterial and venous phases;I:Microscopicyellowish staining of tumor cell nuclei(SP,1020),Ki-67(20%).ABCDEFGHI分子影像学杂志,2023,46(4):661-668http:/www.j- 6663 讨论HGSOC是上皮性卵巢癌中最致命的组织学亚型，主要原因之一是它常常在初次诊断时即已为晚期 12。对于晚期HGSOC患者进行肿瘤细胞减灭术和以铂类为基础的化疗是标准的治疗方法 13。在治疗的前期阶段，大多数卵巢癌患者对手术和基于铂的化疗有反应，但患者经常会复发并对化疗产生耐药性14。若能动态监测肿瘤增殖状态、及时预判肿瘤预后情况，便可有效指导临床适时制定、更新针对性的综合治疗手段，从而达到精准治疗与个体化治疗要求，使卵巢癌患者真正受益。目前临床上常用Ki-67表达水平评估肿瘤的增殖活性 5。在卵巢癌中，有研究指出 Ki-67与卵巢癌的复发和预后之间具有相关性 6；也有研究表明，在接受新辅助化疗治疗后的卵巢癌患者中，Ki-67是卵巢癌患者化疗反应评分及预后的有效生物标志物 15-16。双能量CT通过两种不同的能量谱获取数据，能够提供一组由低到高不同能级下的单能量图像，不同能级的图像具有不同的特征，高能级图像虽然可以有效去除伪影，但会降低图像的对比度，低能级图像的CT值和组织间对比增加，可以提高图像的密度分辨率，低能级的图像能更好地揭示肿块内部结构的细节 17。本研究发现Ki-67高表达组动脉期、静脉期4090 keV单能量CT值均高于低表达组，与既往研究结果一致 10，可能原因是随着Ki-67表达水平的增高，肿瘤组织内血管数量随之增加，血供丰富，肿瘤强化明显，导致注射造影剂后病灶CT值相应增加；不过仅4070 keV单能下CT值的组间差异有统计学意义，且相关系数较高，而80 keV、90keV单能CT值组间差异无统计学意义，提示低能级图像对HGSOC肿瘤增殖活性有一定的预测价值。碘是增强CT扫描时造影剂的关键成分。双能量CT可以通过物质分解原理将碘物质与其他物质区分开来，利用碘图成像获得碘的空间分布，对物质进行密度成像和定量分析，可获得多个参数用于诊断，包括IC和NIC18。本研究中，动脉期与静脉期IC、NIC在两组间的差异均有统计学意义，IC、NIC值与Ki-67表达水平呈正相关关系，诊断效能较高（动脉期AUC值分别为0.781、0.776，静脉期AUC值分别为0.827、0.869）。一项对浸润性乳腺癌的研究也发现动、静脉期 IC、NIC与Ki-67水平呈正相关关系19，这与本研究结果基本一致。分析原因可能是，Ki-67高表达组肿瘤细胞增殖活跃，肿瘤组织生长速度快，肿瘤内血管丰富，因此其碘图相关定量参数高于低表达组。上述结果提示动、静脉期 IC、NIC可能对不同肿瘤细胞的Ki-67表达水平均有一定预测价值。利用不同物质在不同能量水平下表现出不同衰减值的原理，可以通过能谱衰减曲线来区分不同的物质 20。一项对结肠癌的能谱CT研究表明，高分化和低分化结肠癌动脉期的能谱衰减曲线均为下降曲线，且在高侵袭性肿瘤中K值更高，提示能谱曲线有助于判断肿块内部组织类型的分化 21。本研究表明，两组肿瘤的能谱衰减曲线均为下降型曲线，且在动脉期和静脉期中，Ki-67高表达组的K值明显高于Ki-67低表达组，动脉期K40-90 keV=0.95是预测Ki-67低表达的最佳阈值，这与既往研究结果相吻合。分析原因，可能是随着肿瘤细胞Ki-67表达水平的升高，肿瘤的增殖活跃程度也相应增加，单位体积肿瘤细胞数量、肿瘤内部微血管的构成以及肿瘤的代谢产物均会随之改变。以上结果或许提示能谱衰减曲线可一定程度上反映肿瘤内部组织构成。本研究通过Spearman相关性分析表明，动脉期、静脉期4070 keV单能量CT值、K40-90 keV、IC、NIC均与Ki-67表达有较强相关性，而动脉期K40-90 keV与其相关性最高，表明双能量CT多定量参数对Ki-67表达有较高的评估价值，同时可以有效反应肿瘤细胞密度及血管生成情况。其中动脉期碘相关参数相关性优于静脉期，分析原因可能是，Ki-67高表达的卵巢肿瘤细胞密度更高、内部血供更为丰富，动脉期碘对比剂于肿瘤内的分布及代谢均更为迅速。既往国内外双能量CT对卵巢肿瘤的研究多为其鉴别卵巢肿瘤良恶性的诊断效能 9,22-24，而评估卵巢癌肿瘤细胞增殖活性的研究报道较少。本研究首次将双能量CT多定量参数应用于评估HGSOC的Ki-67表达水平，可为临床无创、准确评估HGSOC肿瘤细胞增殖能力提供一种新思路。但本研究也存在一些局限：本研究属于单中心回顾性研究，样本量相对较小；本研究为内部验证，评估结果可能存在偏倚；尽管做了充分考虑，仍无法做到将影像学ROI放置区域与病理切片所选区域完全吻合。综上，患者年龄、发生部位、临床症状、肿瘤最大径、动脉期及静脉期80 keV、90 keV单能下CT值与Ki-67表达水平均无相关性，两组动脉期、静脉期4070 keV单能量CT值、K40-90 keV、IC、NIC的差异有统计学意义，与Ki-67表达水平呈正相关关系。双能CT多定量参数是一种预测HGSOC肿瘤细胞增殖能力的可靠方法，值得在临床应用推广。参考文献：1 Singh N,McCluggage WG,Gilks CB.High-grade serous carcino-ma of tubo-ovarian origin:recent developments J .Histopatholo-gy,2017,71(3):339-56.2 Jiang XY,Tang HJ,Chen TH.Epidemiology of gynecologiccancers in China J .J Gynecol Oncol,2018,29(1):e7.3 Gerdes J,Lemke H,Baisch H,et al.Cell cycle analysis of a cellproliferation-associated human nuclear antigen defined by thehttp:/www.j-分子影像学杂志,2023,46(4):661-668 667monoclonal antibody Ki-67 J .J 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