Clinical Study Of Double Contrast-enhanced Endorectal Ultrasonography In The Evaluation Of Advanced Rectal Cancer

Objective 1.To explore the clinical value of double contrast-enhanced endorectal ultrasonography（DCEUS）in T staging,gross morphology and enhancement pattern of advanced rectal cancer;2.To analyze the time-intensity curve（TIC）of advanced rectal cancer by comparing with normal paraintestinal tissues;3.To determine the time-intensity curve（TIC）of patients before and after neoadjuvant therapy.To explore the value of contrast-enhanced endorectal ultrasonography（DCEUS）in evaluating the efficacy of neoadjuvant therapy by comparing quantitative parameters.Methods 59 patients of advanced rectal cancer—who were first diagnosed by DCE-MRI or Enteroscopic pathological biopsy in the First Affiliated Hospital of Guangxi Medical University-were examined by double contrast-enhanced endorectal ultrasonography（perfusion contrast-enhanced ultrasound and intravenous contrast-enhanced ultrasound）and the results were compared with DCE-MRI staging,from September 2018 to February 2019.The gross morphology and enhancement pattern were evaluated.TIC was mapped for ROI,analyzed quantitatively and compared with normal paraintestinal tissues.14 patients were selected for neoadjuvant therapy to compare the quanti-tative parameters of TIC before and after neoadjuvant therapy.Results 1.59 cases of advanced rectal cancer showed 11 cases of poorly differentiated adenocarcinoma,37 cases of moderately differentiated adenocarci-noma,10 cases of highly differentiated adenocarcinoma and 1 case of malignant melanoma.2.Compared with DCE-MRI,the accuracy of DCEUS in T staging of59 cases of advanced rectal cancer was 89.8%（53/59）,which was in good agreement with DCE-MRI staging（Kappa=0.826,P=0.000）.3.The gross morphology of advanced rectal cancer was divided into three types by contrast-enhanced ultrasound,including 19 cases of protuberance type,27 cases of ulcer type and 13 cases of infiltration type.There was no significant difference in T and N stages between different gross types of advanced rectal cancer（P>0.05）.4.The enhancement pattern of advanced rectal cancer can be divided into three types:homogeneous enhancement in 33 cases,heterogeneous enhancement in 15 cases,and low enhancement in 11 cases.There was no significant difference between different gross types and enhancement patterns（P>0.05）.5.Quantitative analysis of contrast-enhanced ultrasound:（1）TTP,PI,MMT,Slope and AUC in advanced rectal cancer were lower than those in normal paraintestinal tissue(t=-3.385,P_TTP=0.001;t=-4.353,P_MTT=0.000),PI,Slope and AUC were higher than those in normal paraintestinal tissue(t=8.270,P_PI=0.000;t=11.997,P_Slope=0.000;t=3.660,P_AUC=0.001).（2）PI and AUC of 14patients before and after neoadjuvant therapy had significant difference(t=3.778,P_PI=0.005;t=2.341,P_AUC=0.047);TTP,MTT and Slope had no significant difference(t=-0.422,P_TTP=0.684;t=-1.231,P_MTT=0.253;t=1.815,P_Slope=0.107).Conclusion 1.Double contrast-enhanced endorectal ultrasonography is helpful in assessing the clinical T staging of advanced rectal cancer.2.Double contrast-enhanced endorectal ultrasonography and quantitative analys-is are of great value in evaluating the efficacy of neoadjuvant therapy for advan-ced rectal cancer.