The Effect of Ethanol Ablation for the Treatment of Benign Cystic Thyroid Nodules / 대한내과학회지

ABSTRACT

BACKGROUND/AIMS: The aims of this study were to evaluate the efficacy and safety of ultrasound-guided percutaneous ethanol ablation for benign cystic thyroid nodules, and to identify the clinical factors associated with therapeutic outcome. METHODS: We examined 46 patients with benign cystic nodules. After removal of cystic fluid, 99% ethanol was injected under ultrasound guidance. Follow-up ultrasonography was then performed 2 weeks and 6-36 months after the therapy to evaluate the early and late response, respectively. An effective response (ER) was defined as volume reduction > 50% or the absence of any residual cystic lesion; partial response (PR) as a 25-50% volume reduction; and no response (NR) as volume reduction < 25% or a volume expansion. RESULTS: During the early response, ER, PR, and NR were 67.4, 30.4, and 2.2%, respectively. The initial mean cyst volume of 12.0 +/- 7.8 mL (3.4-41.3) was reduced significantly after ethanol ablation therapy to 5.4 +/- 3.2 mL (0-33.0; 55% volume reduction, p < 0.001), and to a final late response volume of 4.4 +/- 3.4 mL (0-23.3; 63% volume reduction, p < 0.01). Except for 6 patients who received additional ethanol injection therapies, ER was obtained in 31 of 40 (77.5%) patients in the late response. A large initial volume was the factor associated with therapeutic failure (p = 0.04). Eleven patients (23%) reported transient mild local pain. CONCLUSIONS: Ultrasound-guided ethanol ablation is a safe and highly effective therapeutic method for cystic thyroid nodules. However, more sophisticated approaches are needed for large cystic nodules.