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

Article information

Ultrasonography. 2021;40(4):623-624

Publication date (electronic) : 2021 April 13

doi : https://doi.org/10.14366/usg.21078

Woojin Cho¹, Jung Suk Sim², So Lyung Jung^,3

¹Department of Otolaryngology-Head and Neck Surgery, Withsim Clinic, Seongnam, Korea

²Department of Radiology, Withsim Clinic, Seongnam, Korea

³Department of Radiology, Yeouido St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea

Correspondence to: So Lyung Jung, MD, PhD, Department of Radiology, Yeouido St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, 10 63- ro, Yeongdeungpo-gu, Seoul 07345, Korea Tel. +82-2-3779-1019 Fax. +82-2-783-5288 E-mail: sljung1@catholic.ac.kr

Received 2021 April 5; Revised 2021 April 5; Accepted 2021 April 13.

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. This might be a limitation of our retrospective study. Further research is necessary. Although the exact dosage of ethanol has not been established yet, the concept of single-session low-dose ethanol ablation (EA) might be important in terms of the basic principle for drug injection, which is to obtain the maximum effect with the minimum amount. Using a small amount of ethanol has the advantages of being easy to handle during the procedure and minimizing the risk of procedure-related complications, including ethanol leakage and patient discomfort.

As you pointed out, Park et al. [2] reported a higher therapeutic success rate in a retention group than in an aspiration group, especially in predominantly cystic nodules. However, the efficacy did not show statistical significance in either the volume reduction rate (P=0.761) or therapeutic success (P=0.070) [2]. In addition, Baek et al. [3] reported high effectiveness despite using an aspiration method after 2 minutes of ethanol retention, and Kim et al. [4] reported that the two techniques (retention only and aspiration after injection) showed similar therapeutic success rates (96.7% vs. 93.3%). Whether there is a statistically significant difference between the two techniques in predominantly cystic nodules also requires further investigation.

We agree that our study includes cases with short-term follow-up, making it necessary to conduct a subsequent study with long-term results. Including your opinions on technical issues, we hope that these discussions and our study could provide basic data for future studies and the standardization of EA procedures.