Application of transrectal elastography and contrast-enhanced ultrasound in evaluation of the efficacy of neoadjuvant therapy for rectal cancer / 中华超声影像学杂志

ABSTRACT

Objective To explore the value of transrectal elastography and contrast-enhanced ultrasound in evaluation of the efficacy of neoadjuvant therapy for rectal cancer.Methods Forty patients with final diagnosis of advanced(T≥3) rectal cancer were respectively examined with transrectal ultrasound (TRUS),endorectal elastography and contrast-enhanced ultrasound(CEUS) before and after neoadjuvant therapy(NET).The tumor size,strain ratio and quantitative parameters of contrast-enhanced ultrasound including arrival time(AT),time-to-peak (TTP),peak intensity(PI) and area under the curve(AUC) were recorded and compared before and after NET.In addition,the TRUS stages and postoperative pathological diagnosis were compared after NET.Results ①There were significant decreases in tumor size and strain ratio after the therapy compared with pre-therapy in all these patients(t =-6.13,P ＜0.001;t =-24.92,P ＜ 0.001).②PI and AUC were lower after NET than those of pre-therapy and the differences were significant(t =-9.66,P =0.001;t =-13.58,P ＜0.001).However,the changes of AT and TTP were no statistical significances (t =-1.17,P =0.307;t =-1.26,P =0.275).③The accuracys of preoperative TRUS for T stage and N stage of tumor evaluated according to pathology were respectively 75.0 ％ (30/40,Kappa =0.593,P =0.000) and 72.5 ％ (29/40,Kappa =0.396,P =0.009).Conclusions Transrectal elastography and contrast-enhanced ultrasound can reflect the pathological changes and perfusion characteristics of lesions in a certain extent and have high value in clinical therapy.