Study On The Clinical Value And Limitations Of Contrast-enhanced Ultrasonography After Thermal Ablation Of Liver Cancers

Part one The value of contrast-enhanced ultrasonography in evaluating the efficacy of follow-up after thermal ablation for liver cancersObjective To investigate the role of contrast-enhanced ultrasonography(CEUS)in evaluating the efficacy of follow-up after thermal ablation therapy for liver cancers.Methods We collected 198 patients with liver cancers treated with thermal ablation from January 2017 to May 2020,with a total of 274 tumors.We retrospectively analyzed liver cancers who were followed up with liver CEUS and contrast-enhanced magnetic resonance imaging(MRI)or contrast-enhanced computed tomography(CECT)within 1~3 months after thermal ablation.In addition,the interval between CEUS and contrast-enhanced MRI or CECT was within one week.We use contrastenhanced MRI or CECT as the diagnostic criteria to analyze the accuracy,sensitivity,and specificity of CEUS in evaluating the efficacy of thermal ablation.We also compared CEUS with contrast-enhanced MRI or CECT in evaluating the consistency of thermal ablation efficacy.Results Within 1~3 months after thermal ablation,contrastenhanced MRI or CECT indicated that 247 of 274 liver cancers were completely ablated,and the complete ablation rate was 90.1%.There were 34 patients who underwent CEUS to evaluate the efficacy of thermal ablation within one week of contrast-enhanced MRI or CECT,with 41 ablation lesions.And we found that contrastenhanced MRI or CECT diagnosed 36 complete ablation and 5 residues,CEUS diagnosed 35 complete ablation,and 6 residues.There was no statistically significant difference between CEUS and contrast-enhanced MRI or CECT in the diagnosis(P>0.05).We found that 34 of the 35 complete ablation lesions,and 4 of the 6 residues suggested by CEUS were consistent with contrast-enhanced MRI or CECT.We found that the accuracy,sensitivity,and specificity of CEUS in evaluating the efficacy of thermal ablation were 92.7%,80.0%,and 94.4%,respectively.There was good consistency between CEUS and contrast-enhanced MRI or CECT in evaluating the efficacy of thermal ablation(Kappa=0.685,PC0.05).Conclusion After thermal ablation of liver cancers,CEUS can accurately assess the effect of thermal ablation,and can achieve the same effect as contrast-enhanced MRI or CECT,and can be used as an effective inspection method in follow-up.Part two The clinical value and limitations of immediate contrast-enhanced ultrasonography after thermal ablation of liver cancersObjective To explore the clinical value and limitations of contrast-enhanced ultrasonography(CEUS)after thermal ablation of liver cancers.Methods We retrospectively analyzed 198 patients with liver cancers treated with thermal ablation from January 2017 to May 2020,with a total of 274 tumors.We divided the lesions into two groups based on the presence or absence of CEUS after 10 to 15 min of thermal ablation.The two groups of lesions were the immediate postoperative CEUS group(below as CEUS group)with a total of 196 liver cancers;without CEUS group(below as non-CEUS group),with a total of 78 liver cancers.We use contrast-enhanced MRI or CECT within 1~3 months after thermal ablation as the standard for diagnosing whether the lesion remains.We compared the complete ablation rate of the two groups and analyzed the influence of the maximum diameter,perivascular liver cancers and border of the tumor in CEUS group on the ablation efficacy.Results We found that after 10 minutes to 15 minutes of thermal ablation,18 of the 196 liver cancers in CEUS group suggested residual tumors and were treated with ablation again.In the end,CEUS indicated that all lesions were completely ablated.Within 1~3 months after thermal ablation,contrast-enhanced MRI or CECT showed that 182(92.9%)of the 196 liver cancers in CEUS group were complete ablation,and 65(83.3%)of the 78 liver cancers in non-CEUS group were complete ablation.Difference of the complete ablation rate was statistically significant(χ2=5.697,P=0.017).In CEUS group,the complete ablation rate of liver cancers with the largest diameter > 3 cm was lower than that of liver cancers ≤ 3 cm(85.2% vs 95.8%,P<0.05).The complete ablation rates of non-perivascular liver cancers and perivascular liver cancers were 93.7% and 90.7%,respectively;the complete ablation rates of liver cancers with clear and unclear boundaries were 94.4% and 91.6%,respectively,and the difference was not statistically significant(P>0.05).Conclusion After thermal ablation of liver cancers,CEUS can promptly detect residuals and guide ablation again,which is an effective measure to improve the success rate of operation.