Anhydrous Ethanol Improves Efficiency of Radiofrequency Ablation for the Treatment of Benign Thyroid Nodules:A Prospective Randomized Controlled Trial

Abstract

Objective To investigate the value of injecting a small amount of absolute ethanol into the benign solid nodules of the thyroid before radiofrequency ablation(RFA)to improve the efficiency of radiofrequency ablation. Methods A total of 98 eligible patients(98 nodules)with pathologically confirmed benign solid nodules who were treated in our center from December 2016 to February 2018 were included and randomized into ethanol ablation(EA)combined with radiofrequency ablation(RFA)group(EA+RFA group)and RFA group,with 49 patients in each group.Routine ultrasound,contrast-enhanced ultrasound(CEUS),and thyroid function test were performed before treatment and 1,3,6,and 12 months after treatment.The general information,treatment time,ablation energy,ablation power,postoperative nodule volume reduction ratio(VRR),symptom score(SS)and cosmetic score(CS),thyroid function level,and incidence of complications were compared between these two groups. Results The mean treatment time [(441.30±243.31)s vs.(790.70±349.82)s;t= 4.403, P=0.000],mean ablation energy [(3.92±2.01)kJ vs.(5.15±2.12)kJ;t=2.709, P=0.009],and mean ablation power [(6.07±1.44)W vs.(7.30±1.29)W;t=3.612, P=0.006] were significantly lower in the EA+RFA group than in the RFA group.At 3,6 and 12 months after surgery,the VRR in the EA+RFA group was(57.73±11.07)%(t=-3.16, P<0.001),(64.40±10.56)%(t=-5.45, P<0.001),and(77.29±8.48)%(t=-10.46, P<0.001),respectively;the VRR in the RFA group was(55.44±13.01)%(t=-1.76, P<0.001),(65.28±11.33)%(t=-5.09, P<0.001),and(75.17±9.84)%(t=-8.93, P<0.001),which were significantly smaller than those before surgery.There was no significant difference in VRR between the EA+RFA group and the RFA group at 1(t=3.41, P=0.33),3(t=2.05, P=0.21),6(t=2.77, P=0.49),and 12 months(t=5.05, P=0.10)after treatment.During the follow-up,no recurrence of nodules was observed on CEUS.In the EA+RFA group,the SS [(1.77±0.86)vs.(5.54±2.15);t=9.63, P<0.001] and the CS[(1.39±0.77)vs.(3.32±0.61);t=10.09, P=0.004]at 12 months after surgery were significantly lower than those before surgery.In the RFA group,SS [(1.63±1.04)vs.(5.90±1.79);t=12.72, P<0.001] and CS [(1.64±0.83)vs.(3.15±0.72);t=8.13, P=0.012] at 12 months after surgery were also significantly lower than those before surgery.The CSS in the EA+RFA group was significantly lower than that in the RFA group [(0.93±0.55)vs.(2.44±0.53);t=-11.70, P=0.007].Both groups had no significant change in thyroid function during the follow-up period,and no serious complications were observed. Conclusion Anhydrous alcohol injection can effectively improve the efficiency of radiofrequency ablation in treating benign solid thyroid nodules and is effective in reducing nodule volume,alleviating compressive symptoms,and decreasing cosmetic discomfort.