Ultrasound-Guided Percutaneous Ethanol Injection for the Treatment of Cystic and Predominantly Cystic Thyroid Nodules: A Single-Centre Experience.

Introduction: Thyroid nodules with cystic and predominantly cystic nodules represent a significant subset. Management strategies range from observation to surgical resection, with minimally invasive options like percutaneous ethanol injection (PEI) emerging as alternative. This study evaluates efficacy and safety of PEI for treating cystic and predominantly cystic thyroid nodules. Methods: A retrospective review of 65 euthyroid patients with cystic and predominantly cystic thyroid nodules treated with PEI at a single centre (January 2018-April 2023) was conducted. Pre- and post-procedure nodule volumes were measured, and clinical outcomes were assessed at 1, 3, and 6 months. A volume reduction ratio of greater than 50% defined efficacy, while incidence and severity of adverse events determined safety. Results: Out of 65 patients, 25 patients had pure cystic nodules and 40 patients had predominantly cystic nodules. The median largest diameter cyst size was 3.7 cm (range, 1.63-10.5 cm), and the median volume of cystic nodules before PEI was 10 ml (range, 1.29-80 ml). Patients with a volume reduction ratio >50% are termed responders. Sixty (92.3%) patients were responders, and 5 (7.7) were non-responders at 3 months follow-up. The response rate of PEI at end of the study (6 months follow-up) was 100%. The total volume reduction was 86.49 ± 5.85% at the end of 6 months. Conclusion: PEI is an effective and safe modality for managing cystic thyroid nodules, offering significant volume reduction with minimal adverse effects and proving its role as a first-line alternative for patients unsuitable for surgery.