Ultrasound-guided ethanol ablation for cystic thyroid nodules: effectiveness of small amounts of ethanol in a single session

Abstract

To evaluate the efficacy of ethanol ablation (EA) in the treatment of cystic thyroid nodules using low dose ethanol regardless of initial volume of the nodule or aspirates. Methods: 61 nodules in 60 patients were treated with EA from October 2013 to January 2020. In each patient, EA was performed only once using less than 5mL ethanol (99.5%) instilled and removed completely after a few minutes of retention. Nodule volume, symptom score, cosmetic score and complications were evaluated before and after treatment. Therapeutic success rate (TSR) and volume reduction rate (VRR) according to nodule volume and properties of the aspirates were evaluated. Therapeutic success was defined as the absence of any residual fluid or sufficient volume reduction (≥50%) with improvement of nodule-related symptoms. Results: 61 nodules were 38 of pure cysts and 23 of predominantly cystic nodules. The initial nodule volume was 21.9 ± 15.2mL (range 4.4-77.2 mL). TSR was 88.5% (100% in pure cysts and 69.6% in predominantly cystic nodules, p<0.001). TSR of pure cysts was 100% regardless of nodule volume and properties of aspirates. In predominantly cystic nodules, TSR and VRR were gradually decreased as volume increases. One patient experienced arrhythmia during the procedure, but completely recovered without sequelae. Conclusion: Single-session EA using low dose ethanol might be effective in the treatment of symptomatic cystic thyroid nodules regardless of initial volume and properties of aspirates, especially in pure cysts.

Technical issues in ultrasound-guided ethanol ablation for thyroid lesions

“…Second, the results of this study [ 1 ] showed that volume reductions after EA were much lower in predominantly cystic nodules than in cystic lesions (65.1% vs. 90.1%). However, in previous studies, EA achieved somewhat higher volume reduction rates for predominantly cystic nodules (74.9%-82.4%) [ 3 ].…”

“…We read with great interest the article published by Cho et al entitled "Ultrasound-guided ethanol ablation for cystic thyroid nodules: effectiveness of small amounts of ethanol in a single session" [ 1 ]. In this article, the authors evaluated whether low-dose (less than 5 mL) ethanol injections were effective for treating cystic and predominantly cystic thyroid nodules.…”

“…Therefore, it is necessary to conduct further studies to determine the appropriate amount of ethanol and to compare the two EA techniques (ethanol aspiration and ethanol retention) for predominantly cystic thyroid nodules. Furthermore, the ethanol retention times in the study varied substantially (range, 0.9 to 13.0 minutes) [ 1 ], which was an inevitable limitation of its retrospective design.…”

“…In conclusion, Cho et al [ 1 ] reported a low-dose ethanol method for the treatment of symptomatic cystic and predominantly cystic thyroid nodules. Although the results were acceptable, the use of a low dose in patients with predominantly cystic thyroid nodules should be carefully considered.…”

Re: Technical issues in ultrasound-guided ethanol ablation for thyroid lesions

“…We greatly appreciate your detailed and constructive comments. In our study, we defined a "low dose" as less than 5 mL [ 1 ]. However, we did not propose a precise amount of ethanol according to the nodule volume or the cystic nature of the thyroid nodule.…”