The Value Of Multiparametric MRI In The Study Of Pelvic Lymph Node Metastasis In Stage ?B1??A1 Cervical Cancer

Objective:To investigate the value of multiparametric MRI,including conventional MRI,diffusion weighted imaging(DWI)and dynamic contrast-enhanced MR imaging(DCE-MRI)in demonstrating the metastatic potential of primary tumor and differentiating metastatic lymph nodes(MLN)from non-metastatic lymph nodes(NMLN)in stage ?B1??A1 cervical cancerMethods:57 patients with ?B1??A1 cervical cancer confirmed by pathology in our hospital between January 2016 and June 2018 were retrospectively analyzed.All patients underwent preoperative pelvic MRI,including DWI and DCE-MRI.Primary tumor and all lymph nodes visible on the MR images were evaluated by two experienced radiologists,who were blinded to the pathological results.The two radiologists measured the apparent diffusion coefficient(ADC)values(ADCmean,ADCmin,and ADCmax)and quantitative dynamic contrast-enhanced MR imaging(DCE-MRI)parameters(Ktrans,Kep,and Ve)of primary tumors and lymph nodes,and the short-axis diameter and long-axis diameter of lymph nodes to characterize the shape of lymph nodes(round[ratio of long-to-short axis diameter<1.2],oval[ratio of long-to-short axis diameter 1.2-1.5],elongated[ratio of long-to-short axis diameter>1.5]),the signal characteristics were also recorded by the two radiologists.Only the lymph nodes that were undoubtedly matched between the MR images and postoperative pathology were eventually included in this study.The agreement between two radiologists was assessed by the interclass correlation coefficient(ICC)and kappa statistics.Differences of parameters between metastatic and non-metastatic primary tumors,MLN and NMLN were analyzed by Mann-Whitney test and chi-square test.Logistic regression was used for multivariate analysis and established combining prediction models,and receiver operating characteristic analysis was used to compare the diagnostic performance of individual MRI parameters and combining predictors.Delong test was used for compare the differences of the values of area under the curve(AUC)between different parametersResults:1.19 patients had lymph node metastasis,38 patients without lymph node metastasis A total of 94 lymph nodes were evaluated,including 30 MLNs and 64 NMLNs 2.The ICC values of the parameters of the primary tumor between the two radiologists ranged from 0.821 to 0.993;the ICC values of the parameters of the pelvic lymph nodes between the two radiologists ranged from 0.878 to 0.997;the Kappa value of signal characteristics between two radiologists was 0.833,all with good consistency 3.There were no significantly difference in ADC values and quantitative DCE-MRI parameters between metastatic and non-metastatic primary tumors(P>0.05)4.There were no significantly differences of shapes between MLNs and NMLNs(P>0.05).The signal characteristics were significantly different between MLNs and NMLNs(P=0.001),heterogeneous signal was more commonly seen in MLNs than in NMLNs.The short-axis diameter of MLNs(9(6,10)mm)was higher than NMLNs(5.5(4,7)mm),the difference was statistically significant(P<0.001).The ADCmean(0.784(0.708,0.887)*10-3mm2/s),ADCmin(0.656(0.598,0.791)*10-3mm2/s),and ADCmax(1.046(0.933,1.204)*10-3mm2/s)of MLNs were all lower than the ADCmean(1.065(0.938,1.109)*10-3mm2/s),ADCmin(0.910(0.782,1.015)*10-3mm2/s),and ADCmax(1.219(1.134,1.301)*10-3mm2/s)of NMLNs,the differences were statistically significant(P<0.001).The Ktrans(1.007(0.595,1.423)min-1),Kep(1.307(0.841,1.746)min-1),and De(0.652(0.461,0.888))of MLNs were all higher than the Ktrans(0.466(0.247,0.732)min-1),Kep(0.852(0.509,1.360)min-1),and Ve(0.459(0.278,0.660))of NMLNs,the differences were statistically significant(P<0.05).In the individual MRI parameters,ADCmean showed a highest AUC of 0.849(0.747?0.951),with a sensitivity of 76.7%and specificity of 90.6%5.The combining predictor of short-axis diameter,ADCmean and Ktrans showed a highest AUC of 0.930(0.882?0.979),the cut-off value was 0.265,with a sensitivity of 86.7%and specificity of 85.9%.The AUC of combining predictor was significantly higher than that of ADCmean(P<0.05)Conclusion:1.The parameters of DWI and DCE-MRI of the primary tumor in stage ?B1??A1 cervical cancer could not demonstrate the metastatic potential of the primary tumor 2.The signal characteristics and the short-axis diameter of the lymph nodes,as well as the DWI and DCE-MRI parameters of the lymph nodes,could discriminate pelvic MLNs from NMLNs of the stage ?B1??A1 cervical cancer patients,and ADCmean showed a highest AUC in the individual MRI parameters3.Compared with individual MRI parameters,the combination of multiparametric MRI could improve the diagnostic performance of the lymph node metastasis.