Abstract: Objective To investigate the influencing factors of anhydrous ethanol ablation in the treatment of benign cystic thyroid nodules and possible measures. MethodsA total of 102 benign cystic thyroid nodules patients who were treated with anhydrous ethanol in our department from January 2014 to June 2016 were enrolled in the study. The patients underwent ethanol flush or ethanol flush combined with local injection and their changes in the volume of nodules were evaluated before and after treatment, and the corresponding efficacies were compared. Meanwhile, the influencing factors of the above treatments were analyzed. ResultsAfter anhydrous ethanol ablation, the average volume of nodules were reduced from (15.7 ± 14.3) ml to (3.0 ± 2.5) ml, with an effective rate of 84.5%. Ethanol flush alone resulted in decreases in the average nodule volume from (16.6 ± 13.5) ml to (4.7 ± 3.1) ml, with an effective rate of 76.9%. Ethanol flush combined with local injection resulted in decreases in the average nodule volume from (14.8±12.2) ml to (2.1 ±1.4) ml, with an effective rate of 90.2%. The combined treatment showed a higher effective rate than ethanol flush alone. The independent predictors for the efficacy of anhydrous ethanol ablation include therapeutic methods, the volume before treatment volume and solid components of the nodules, where the volume before treatment volume and solid components of the nodules were the independent predictors for the efficacy of ethanol flush alone. No independent factor was found to be associated with the efficacy of the combined treatment. ConclusionsBoth ethanol flush and ethanol flush combined with local injection are effective to treat benign cystic thyroid nodules. Compared with ethanol flush alone, the combined treatment is more effective to treat nodules with large size or more solid components.