Ethanol Ablation for the Treatment of Cystic and Predominantly Cystic Thyroid Nodules

Objective: To determine the efficacy and safety of percutaneous ethanol injection (PEI) for the treatment of symptomatic cystic thyroid nodules. Patients and Methods: Retrospective analysis of patients with benign cystic thyroid nodules treated with PEI from February 1, 2000, through October 31, 2016. The main outcomes were efficacy, defined as symptom relief or reduction in nodule volume of 50% or more, and safety, defined as no or minor adverse events. Results: Twenty patients had PEI. Mean age at the time of PEI was 50 years, and 13 (65%) were women; all patients were euthyroid. Twelve patients (60%) had complex cystic thyroid nodules (>50% cystic component), with the rest being purely cystic. The median largest diameter of the thyroid cyst was 4.5 cm (interquartile range [IQR], 3.2-5.3 cm; range, 2.3-8.0 cm); the median volume pre-PEI was 19.6 mL (IQR, 10.4-48.5 mL; range, 2.8-118.1 mL). The median amount of cystic fluid drained before PEI was 13.5 mL (IQR, 6.8-32.3 mL), and the median amount of ethanol administered was 3 mL (IQR, 2-5 mL; range, 0.5-20 mL). After median follow-up of 2 years, 17 of 19 patients (89%) were asymptomatic. Of 10 patients with available imaging on follow-up, 7 (70%) had a 50% or greater reduction in nodule volume (median volume decrease, 75.64% [IQR, 41.40%-91.99%]). Adverse effects occurred in 4 patients (20%) and were mild and temporary (slight pain, vagal reaction, and bleeding into the cyst). Conclusion: Percutaneous ethanol injection seems to be a safe and effective alternative to surgical resection for patients with purely or predominantly cystic thyroid nodules and compressive symptoms who decline surgery or are not good surgical candidates.