Endocrine Abstracts

JOINT1981

Introduction: Large thyroid nodules can cause compressive symptoms, such as a sense of tightness, dysphagia, dysphonia and dyspnea. In these cases, surgery (thyroidectomy/lobectomy) is indicated. When surgery and/or general anesthesia are contraindicated (e.g., age, comorbidities, etc.) or if the patient refuses surgery, the guidelines recommend that cytologically benign and non-functioning nodules, solid or mixed, can be treated with ultrasound-guided thermal ablation (TA), a minimally invasive treatment aimed at reducing nodule volume and reducing or eliminating compressive symptoms. TA can be performed using radiofrequency (RFA), microwaves (MWA), laser, or ultrasound. According to literature data, the expected volume reduction 12 months after treatment is 50%-84% with RFA and 74%-90% with MWA.

Methods: In our cohort, we included 36 patients who underwent TA (34 RFA and 2 MWA) at our University Hospital. We evaluated the volumetric reduction with one or more post-TA ultrasound examinations (at 45 days, 3 months, 6 months and 12 months after TA).

Results: Pre-treatment average volume of the nodules was 18.2 ml. Twenty-six patients had a 45-day follow-up with an average volume reduction of 38% (min 7.2% - max 82%, average volume = 13 ml). Thirty-two patients had a 3-month follow-up with an average volume reduction of 47% (min 7% - max 83%, average volume = 9.5 ml). Twenty patients had a 6-month follow-up, with an average volume reduction of 55.9% (min 0% - max 92.2%, average volume = 7.7 ml). Twenty patients had a 12-month follow-up, with an average volume reduction of 60.2% (min 23.1% - max 91.8%, average volume = 5.1 ml). Only one patient had a therapeutic failure, with a volumetric reduction of 7% at 45 days and a subsequent volumetric increase to a volume close to the pre-treatment volume at the 6-months ultrasound follow-up. Only 3 patients (8.3%) experienced minor complications (moderate pericapsular hematoma, first-degree skin burn of 4 millimeters, transient hoarseness); no major complication nor hypothyroidism was reported.

Conclusion: The volumetric reduction in our case series is similar to that reported in the literature. Thermal ablation is a valid alternative to surgery, eliminating symptoms, reducing nodule volume, preventing nodule enlargement and avoiding hypothyroidism. Pre-treatment nodule volume is a predictive factor for treatment outcomes. To date, other clinical and ultrasound parameters predicting volumetric reduction and long-term symptomatic response to the treatment are still debated.