SUN-LB85 Short-Term Outcomes of Radiofrequency Ablation of a Toxic and a Non-Toxic Benign Thyroid Nodule

Abstract

Background: Radiofrequency ablation (RFA) of benign thyroid nodules has been shown to be a safe and effective minimally invasive treatment for benign thyroid nodules, based on many years of international experience. Thyroid specific devices have recently become available in the US. Here, we present representative examples of our early experience with RFA for both non-toxic and toxic thyroid nodules in our outpatient center.Clinical Cases: Case 1: A 39 year-old woman presented with subclinical hyperthyroidism, with a TSH of 0.013 uIU/mL (0.45-4.5 uIU/mL). Evaluation showed bilateral autonomously functioning thyroid nodules. Both nodules were predominantly solid with no suspicious features and grade 3 Doppler flow, and were benign (Bethesda II) on UG-FNA. She declined treatment with total thyroidectomy, radioactive iodine, or long-term thionamides, and decided to proceed with RFA, after pre-treatment with methimazole. We decided to target the right lobe nodule first, as it was larger, with a volume of 2.63 ml. The danger triange and vagus nerve were identified, and then we injected local anesthetic using the pericapsular lidocaine technique. We then performed ultrasound-guided RFA of this nodule, using an RF generator with an internally cooled 18-gauge electrode, with a length of 7 cm and an active tip of 7 mm. Power was set at 25 Watts. The trans-isthmic approach and moving shot technique were used. Total energy delivery was 3078 WS. At the end of the procedure, we visualized a transient hyperechoic zone and there was absence of Doppler flow throughout the nodule. She tolerated the procedure well without complications. Methimazole was stopped after the procedure. At the 3-month follow-up, the nodule had decreased in volume by 72.5% and had no internal Doppler flow; TSH normalized (1.37 uIU/mL), so we decided not to proceed with RFA of the left superior toxic adenoma. Case 2: A 49 year-old woman presented with a large right lobe thyroid nodule with a volume of 6.13 ml, which was causing dysphagia and dysphonia. It was predominantly solid with no suspicious features and grade 3 Doppler flow. TSH was normal. It was benign (Bethesda II) on UG-FNA on 2 occasions. She declined surgical therapy, and decided to proceed with RFA. We performed local anesthesia and then RFA in a similar fashion to case 1, with a power of 20-40 Watts. Total energy delivery was 11,491 WS. There were no complications. At the 3-month follow-up, TSH remained normal, and the volume of the ablated nodule had decreased by 59.9%. There was no intranodular Doppler flow. Her compressive symptoms completely resolved.Conclusion: These cases are representative of our early experience with thyroid RFA in the USA, and showcase its safety, efficacy and feasibility in the outpatient setting, for patients with toxic or non-toxic symptomatic thyroid nodules.