动态对比增强MRI定量参数及细胞外体积分数在非小细胞肺癌分型诊断及淋巴结转移预测中的应用

Role of quantitative dynamic contrast-enhanced MRI parameters and extracellular volume fraction in differentiating non-small cell lung cancer subtypes and predicting lymph node metastasis

目的探讨动态对比增强磁共振成像(DCE-MRI)定量参数和细胞外体积(ECV)分数在非小细胞肺癌(NSCLC)分型诊断及淋巴结转移预测中的价值。方法回顾性队列研究。纳入2020年9月—2022年12月山东第一医科大学附属省立医院病理检查确诊为NSCLC的70例患者临床和MRI资料。70例中,男55例、女15例,年龄45~74(60.7±6.9)岁。患者均在治疗前1周内行DCE-MRI和增强T1mapping检查,测量定量参数容量转移常数(K^(trans))、速率常数(K_(ep))和血管外细胞外间隙容积分数(V_(e))。在MRI扫描后3 d内采集患者的静脉血检测血细胞压积,根据T1mapping检测T1值计算ECV分数。根据患者NSCLC病理分型不同将患者分为腺癌组(41例)和鳞癌组(29例),根据有无淋巴结转移分为有转移组(28例)和无转移组(42例)。观察指标:(1)比较不同分组患者的性别、年龄、肿瘤分化程度、肿瘤最大径等临床基线资料;(2)采用组内相关系数(ICC)检测不同观察者间检测DCE-MRI定量参数及ECV分数结果的一致性;(3)比较不同分组患者间DCE-MRI定量参数及ECV分数的差异;(4)分析不同分组间有差异的参数对NSCLC分型的诊断效能及对NSCLC淋巴结转移的预测效能;(5)分析DCE-MRI的定量参数V_(e)与ECV分数的相关性。结果(1)腺癌组与鳞癌组患者的年龄、肿瘤分化程度、肿瘤最大径比较差异均无统计学意义(P值均>0.05),而性别间差异有统计学意义(χ2=13.50,P<0.001)。淋巴结转移组与无转移组患者的性别、年龄、肿瘤分化程度、肿瘤最大径比较差异均无统计学意义(P值均>0.05)。(2)不同观察者间检测DCE-MRI定量参数及ECV分数结果的一致性均较高:ICCK^(trans)=0.815,ICCK_(ep)=0.835,ICCV_(e)=0.871,ICCECV分数=0.853。(3)腺癌组DCE-MRI定量参数K^(trans)、K_(ep)及V_(e)分别为0.23(0.19,0.29)、0.79(0.60,0.90)、0.32(0.24,0.45),均高于鳞癌组的0.14(0.12,0.20)、0.61(0.52,0.78)、0.25(0.20,0.38),差异均有统计学意义(Z=4.76、2.21、2.44,P值均<0.05);2组间ECV分数差异无统计学意义(P>0.05)。有转移组的ECV分数为0.33±0.07,高于无转移组的0.26±0.06,差异有统计学意义(t=4.44,P<0.001);2组间DCE-MRI定量参数K^(trans)、K_(ep)及V_(e)差异均无统计学意义(P值均>0.05)。(4)选取腺癌组和鳞癌组间差异有统计学意义的参数K^(trans)、K_(ep)、V_(e),分析其对NSCLC分型的诊断效能:K^(trans)的诊断效能最佳,K^(trans)的曲线下面积(AUC)为0.836(95%可信区间0.743~0.929),当截断值为0.208时,其诊断腺癌与鳞癌的灵敏度为68.3%、特异度为86.2%。选取有转移组和无转移组间差异有统计学意义的ECV分数,分析其对NSCLC淋巴结转移的预测效能:ECV分数的AUC为0.764(95%可信区间0.652~0.877),当截断值为0.293时,ECV分数预测淋巴结转移的灵敏度为64.3%、特异度为81.0%。(5)NSCLC患者ECV分数与V_(e)无相关性(rs=0.071,P=0.558)。结论DCE-MRI参数K^(trans)、K_(ep)、V_(e)在诊断NSCLC的分型中,K^(trans)的诊断效能最佳,ECV分数在预测NSCLC淋巴结转移中有较好的预测价值。

Objective This study aimed to investigate the value of dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI)parameters and extracellular volume(ECV)fraction in the diagnosis of non-small cell lung cancer(NSCLC)subtypes and prediction of lymph node metastasis.Methods A retrospective cohort study was performed,and the clinical and MRI data of 70 patients diagnosed with NSCLC by pathological examination from September 2020 to December 2022 in the Provincial Hospital of Shandong First Medical University were included.The patients aged 45-74(60.7±6.9)and were composed of 55 males and 15 females.The patients underwent DCE-MRI and enhanced T1 mapping within 1 week prior to treatment.The quantitative parameters,namely,volume transfer constant(K^(trans)),flux rate constant(K_(ep)),extracellular extravascular volume fraction(V_(e))were measured.V_(e)nous blood was collected from the patient within 3 days of the MRI scan,and the patient's hematocrit was then measured.The detection of T1 values based on T1 mapping was used to calculate ECV fraction.The patients were divided into adenocarcinoma group(41 cases)and squamous carcinoma group(29 cases)according to NSCLC pathological typing.The patients were divided into groups with metastasis(28 cases)and without metastasis(42 cases)according to the presence or absence of lymph node metastasis.The observation indexes were obtained as follows:(1)Clinical baseline data,such as gender,age,degree of tumor differentiation,and maximum diameter of lesions in different groups of patients were compared;(2)The consistency between observers in detecting quantitative DCE-MRI parameters and ECV fraction results was evaluated;(3)the quantitative DCE-MRI parameters and ECV fraction of different groups were compared;(4)the diagnostic efficacy of parameters that differed among subgroups was analyzed for the typing of NSCLC,and the predictive efficacy for the metastatic status of NSCLC lymph nodes was evaluated;(5)the correlation between the quantitative parameter V_(e)of DCE-MRI and ECV fraction was analyzed.Results(1)No statistically significant differences in age,degree of tumor differentiation,and maximum tumor diameter were found between the adenocarcinoma and squamous carcinoma groups(all P values>0.05),whereas the difference in gender between the groups was statistically significant(χ2=13.50,P<0.001).Differences in gender,age,degree of tumor differentiation,and maximum tumor diameter between patients with lymph node metastasis and patients without metastasis were not statistically significant(all P values>0.05).(2)The levels of inter-observer agreement in detecting quantitative DCE-MRI parameters and ECV fraction were defined as follows:ICCK^(trans)=0.815,ICCK_(ep)=0.835,ICCV_(e)=0.871,and ICCECV fraction=0.853.Good agreement was identified between the observers.(3)The quantitative DCE-MRI parameters K^(trans),K_(ep),and V_(e)in the adenocarcinoma group were 0.23(0.19,0.29),0.79(0.60,0.90),and 0.32(0.24,0.45),respectively,which were higher than those in the squamous carcinoma group(0.14[0.12,0.20],0.61[0.52,0.78],and 0.25[0.20,0.38]).The differences between the groups were statistically significant(Z=4.763,2.212,2.438;all P values<0.05).No statistically significant difference in ECV fraction was found between the groups(P>0.05).The ECV fraction of the group with metastasis was 0.33±0.07,which was higher than that of the group without metastasis(0.26±0.06),and the difference was statistically significant(t=4.436,P<0.001).Differences in the quantitative parameters K^(trans),K_(ep),and V_(e)of DCE-MRI between the groups were not statistically significant(all P values>0.05).(4)In the adenocarcinoma and squamous carcinoma groups,K^(trans),K_(ep),and V_(e)with statistically significant differences were used in analyzing the diagnostic efficacy of NSCLC subtypes,and K^(trans)had the best diagnostic efficacy,which had an area under the curve(AUC)of 0.836(95%confidence interval[CI]0.743-0.929),sensitivity of 68.3%,and specificity of 86.2%for the diagnosis of adenocarcinoma and squamous carcinoma when the cutoff value was 0.208.Difference in ECV fraction between the groups with and without lymph node metastasis was statistically significant,and thus the predictive performance of K^(trans)for the lymph node metastasis status of NSCLC was analyzed.The AUC of ECV fraction was 0.764(95%CI 0.652-0.877).When the cutoff value was 0.293,the sensitivity of ECV fraction in predicting lymph node metastasis was 64.3%,and the specificity was 81.0%.(5)No correlation was found between ECV fraction and V_(e)in NSCLC(rs=0.071,P=0.558).Conclusion Among the DCE-MRI parameters,K^(trans)had the best diagnostic efficacy in the diagnosis of NSCLC subtypes,and ECV fraction had a good predictive value in predicting NSCLC lymph node metastasis.