IVIM-DWI For Early Assessing Treatment Effect Of Colorectal Liver Metastases Treated With Cytotoxic Plus Antiangiogenic Drug

Purpose:To assess the value of intravoxel incoherent motion(IVIM)of Diffusion-weighted imaging(DWI)technique in the assessment of Colorectal Cancer Liver Metastases treated with chemotherapy plus antiangiogenic therapy.Methods:34 patients with unresectable colorectal liver metastases diagnosed by pathology from October 2014 to January 2019 were enrolled received chemotherapy plus antiangiogenic therapy.1.5 T conventional MRI scan and 9 B-value(0-1000s/mm2)IVIM-DWI sequence scan were performed for All patients before and 3 weeks after the first treatment,and only conventional MRI scans were performed 6 and 12 weeks after initial treatment.DWI data were postprocessed using software to extract the IVIM parameters including perfusion fraction(f),true diffusion coefficient(D),and pseudodiffusion coefficient(D*).The response evaluation was based on Response Evaluation Criteria in Solid Tumors version 1.1,the longest diameter of the tumor was measured on T1-weighted dynamic contrast-enhanced images.Results:There were 16 responding and 18 nonresponding patients.f(baseline vs after first cycle of treatment[mean±SD]:0.221±0.033vs0.187±0.033;p=0.001)and D(1.246±0.300×10-3mm2 vs 1.425±0.280±0.330×10-3mm2/s;p=0.003)showed a significant change after the first cycle of chemotherapy in the response group,whereas D*showed no significant change;In the nonresponse group,D increased from 1.159±0.189×-3mm2/s before treatment to 1.218±0.155×10-3mm2/s(p=0.039)after treatment,but f and D*showed no significant change.In addition,f is significantly higher in the response group than nonresponse group(0.221±0.033 VS 0.175±0.040,p=0.003)before first treatment.The f Percentage change obtained the largest Area Under Curve(AUC=0.797)in ROC analysis.the FLDA approach yielded an AUC of 0.819.Conclusions:IVIM parameters f and D can effectively evaluate the treatment response of chemotherapy combined with antiangiogenic drugs in colorectal liver metastases at early stage,and f can predict the treatment response of patients before treatment.