Evaluation Of Clinical Value In Monitoring And Predicting Treatment Efficacy Of Advanced Cervical Cancer Under Concurrent Chemoradiotherapy With IVIM And DWI

Objective To evaluate the value of parameters related to voxel incoherent motion（IVIM）and diffusion weighted imaging（DWI）in monitoring and predicting the treatment efficacy of locally advanced cervical cancer under concurrent chemoradiotherapy.Methods 21 patients with locally advanced cervical cancer undergoing concurrent chemoradiotherapy in our hospital from August 2016 to December 2017 were prospectively enrolled in this study.All patients did not undergo any treatment before the examination.The MRI of routine scan sequence,DWI with 2b value（0,800s/mm²）and IVIM sequence with 10 b values（0,50,100,150,200,300,400,600,800,1000s/mm²）were performed 1 weekbefore CCRT,2 and 4 weeks after the initiation of CCRT,and 4 weeks after the end of CCRT,respectively.The Siemens Workstation and the MITK post-processing software were used to measure the parameters at different time points before and after CCRT,including the apparent diffusion coefficient（ADC）and IVIM-based parameters（D,D*and f）,as well as the maximum tumor diameter at each scan time point,and calculate the change rate of each parameter after treatment and the maximum diameter reduction rate of tumor.All patients were divided into complete remission（CR）and partial remission（PR）groups according to RECIST 1.1 criteria,the parameters and their percentages were compared between the two groups at different time points by independent-samples-t test,ROC curves were applied to analyze the effect of the response evaluation of parameters and their change percentages（Δ%）,Pearson correlation test were applied to analyze the relationship between the parameters as well as their change percentages（Δ%）and tumor regression rate.Results:1)Before CCRT,the CR group had lower ADC and higher f value than PR group（all P<0.05）,There was no significant difference in D value,D*and maximum tumor diameter before CCRT between the two groups.（P>0.05）.2)After CCRT,a)both ADC values and D values in CR and PR groups were higher than those before treatment（P<0.05）.The CR group exhibited higher ADC and D than PR group（P>0.05）,as well as higherΔ%ADC andΔ%D than PR group（P<0.05）.b)After treatment,the f values were higher than those before treatment（P<0.05）,the f values kept increased first and then decreased after 4 weeks of the treatment in CR group.The f values of PR group kept on rising（P<0.05）.There was no significant difference in f value between the two groups.The CR group exhibited higherΔ%f than the PR group at 4 weeks after the end of CCRT（P<0.05）.c)After treatment,the D*of the CR group and the PR group decreased first and then increased after the treatment.There was no statistical difference of D*andΔ%D*within and between the two groups at each time point（P>0.05）.d)The maximum diameter of tumor of CR group and PR group kept on decreasing during CCRT.The CR group exhibited higherΔ%d than PR at each time point after treatment,and there was a statistical difference between the two groups at 4weeks after the initiation of CCRT and 4weeks after the end of the CCRT.（P<0.05）3)The area under the curve for f-value was greater than ADC（AUC=0.92,0.78）.The area under the curve forΔ%D after two weeks and four weeks of treatment was greater thanΔ%ADC（AUC=0.868,0.846,0.803,0.798）.Conclusions:1)Both IVIM and DWI are helpful in monitoring and predicting the treatment efficacy of cervical cancer under chemoradiotherapy.2)When f≥(12.15x 10^-3)%before treatment,the tumor can be completely relieved 4 weeks after the end of CCRT.3)BothΔ%D andΔ%ADC at 2 weeks and 4 weeks after treatment can predict the CR and PR groups,and the diagnostic efficacy is similar.