Usefullness Of Contrast-Enhanced Ultrasound To Evaluate The Responses Of Radiofrequency Ablation For Hepatocellular Carcinoma After 24 Hours:Comprasion With Contrast-Enhanced MRI

Objective:To assess the application value of Contrast-Enhanced Ultrasound (CEUS) in patients undergoing radiofrequency ablation for hepatocellular carcinomas (HCC) after 24 hours, compared with contemporaneous Contrast-Enhanced Magentic Resonance(CEMRI)Methods:From January 2014 to August 2015,33 HCCs from 27 patients were treated with RFA. After 24 hours, CEUS and CEMRI were then used to evaluate the effect of RFA. Radiofrequency ablation margin, internal necrosis and local tumor remain were evaluated. One month later CECT/CEMRI was used as the gold standard of evaluation. Then compared the local recurrence rate between the sufficient safety margin group and the insufficient safety margin group after 4-14 months’follow up to assess the value of 24 hours evaluation of therapeutic efficacy of RFA for HCC by CEUS. Local residual lesions need secondary radiofrequency ablation.Results:CEUS judged 33 cases as Complete ablated, while CEMRI identified 31 cases. Zero case diagnosed as’incomplete’by CEUS, while CEMRI had 2 cases. The difference had no statistically significant, the Fisher exact test result was P=0.492. CEUS judged 7 cases as complete ablated with safety margin<5mm, two of the seven lesions(6.1%) were proved tumor residual by CECT one month later, which was gave supplementary treatment to achieve sufficient safety margin by CEUS 24 hours later. The other 31 cases (93.9%)(include 26 cases as complete ablated with safety margin ≥5mm and 5 cases as complete ablated with safety margin< 5mm by CEUS) were proved complete response(CR) by CECT/CEMRI one month later. Five of these 33 cases from the CEUS group had local recurrences after 4-14 months’follow up, inclued 3 of the 5 lesions with safety margin<5mm and 2 of 28 lesions with safety margin ≥5mm (include two local residual lesion which accepted secondary radiofrequency ablation), local recurrence rate was 60.0% and 7.1%, respectively. The difference had statistically significant, the Fisher exact test result was P=0.017.Conclusions:CEUS can timely, dynamically, directly reflect the residual tumor and the safety margin of HCC, with the same diagnosis effect compared with CEMRI, and can be used to assess the early efficacy of RFA for HCC as the first choose.