Side-by-side Contrast Enhanced Ultrasound In The Early Evaluation Of Microwave Ablation For Hepatocellular Carcinoma

Objective:To explore the accuracy and clinical application value of side-by-side contrast enhanced ultrasound(side-by-side CEUS)in the early(1~3 days)evaluation of hepatocellular carcinoma(HCC)after microwave ablation(MWA).Materials and methods:A total of 140 HCC patients(140 lesions)who underwent MWA in our hospital were selected.Conventional contrast-enhanced ultrasound(CEUS)were performed within 7 days before MWA and dynamic images were stored at least 120 seconds.Side-by-side CEUS was performed 1~3 days and CECT 1 month after MWA to judge the therapeutic effect.Contrast enhanced MRI(CEMRI)were taken alternatively for patients who had a allergic reaction history to CECT.For side-by-side CEUS and CECT,MWA effects were classified as follows:(1)complete necrosis response with safety margin?5 mm(CRSM+);(2)complete necrosis response but with safety margin<5 mm(CRSM–);(3)‘residue',incomplete necrosis of HCC.US-guided biopsy were conducted subsequently for ‘residue' lesions in side-by-side CEUS results,and pathologically positive lesions received supplementary MWA.The pathological diagnosis and follow-up results at least 2 years after MWA were used as the gold standard.The accuracy,reliability and clinical value of side-by-side CEUS and CECT were compared with gold standard.Results:One patient in this study was lost to follow up less than 2 years after MWA.Side-by-side CEUS judged 126 cases as CRSM+,2 cases CRSM-,and 11 cases‘residue'.The pathological diagnosis and follow-up results confirmed 15 cases as local progression and 124 cases complete treatment.ROC curve for side-by-side CEUS was established,area under the curve(AUC)was 0.861.CECT judged 133 cases as CRSM+,3 cases CRSM-and 3 cases ‘residue'.At the deadline of follow-up,6 cases of local progression and 133 cases complete treatment was confirmed.ROC curve for CECT was established,AUC = 0.915.The results were further divided intocomplete ablation and incomplete ablation.In this study,we defined CRSM-and‘residue' as incomplete ablation,CRSM+ as complete ablation,and this classification achieved higher accuracy(AUC were 0.859,0.913 separately).Compared with gold standard,the sensitivity of side-by-side CEUS and CECT in evaluating the therapeutic effect of HCC was 73.3% and 83.3%;the specificity,98.4% and 99.2%;the accuracy,95.7% and 98.6%,the positive predictive value,84.6% and 83.3%,the negative predictive value,95.7% and 98.6%.Lost to follow-up within 2 years and supplemental MWA patients were excluded,there was no significant difference between side-by-side CEUS and CECT results(P>0.05).For CRSM+ group and CRSM-group,the local progression between side-by-side CEUS and CECT were no significant differences either(P>0.05).At the end of this study,the number of cases of local progression of HCC was 15.Among them,adjacent to major blood vessels,the heart,hepatic portal and other dangerous locations have more cases of local progression(5/18).Conclusions:1.Side-by-side CEUS has high accuracy,reliability and clinical application value compared with the gold standard,there was no significant difference between side-by-side CEUS and CECT results.2.The accuracy was higher if we define CRSM-and ‘residue' as incomplete ablation,and CRSM+ as complete ablation.