MON-395 Experience in the Treatment of Toxic Adenomas Using Percutaneous Ablation Techniques in a Tertiary Care Unit

Abstract Disclosure: M.A. Alvarez Castillo: None. L.F. Sanchez Arriaga: None. A. Segovia-Palomo: None. Introduction: Toxic adenomas (TA) represent 3-10% of the causes of primary hyperthyroidism (PH). It predominantly causes subclinical hyperthyroidism, which is why patients usually dont present thyrotoxicosis symptoms, with the tumor component being the symptomatic form of detection. The treatment of choice, according to the tumor size, is surgical or using I131; these therapies dont exempt morbidity or the need for hormonal replacement treatment. Chemical or thermal percutaneous ablation (PA) techniques have been described as effective therapeutic alternatives for this pathology. Objective: Evaluate the efficacy and safety of PA for the treatment of patients with PH due to TA. Material and methods: Observational, longitudinal, retrospective and analytical study. 17 patients with a diagnosis of TA were included, who received treatment with PA. Descriptive statistics were used for the analysis. Results: The mean age was 41.1(14.9) years, 16 (94.1%) were women, identification time was 17.4(10.53) months, 6(35.3%) were asymptomatic. The predominant form of identification was due to increased volume (64.7 %), 13 (76.5%) were located in the right lobe, major axis of 35.3 (14.1) mm, with a volume of 14.1(14.5)ml, 10(58.8%) were solid and 7(41.2%) mixed, mode on a cosmetic scale was palpable without affection. Mean TSH 0.03(0.03), FT4 1.45(0.71), FT3 5.01 (1.33). 15 (88.2%) were treated with thiamazole and 7 (41.2%) with propranolol. 11(64.7%) were treated with chemical ablation (CA) with ethanol and polidocanol and 6(35.3%) with radiofrequency thermal ablation (RFT). The mode of sessions was 2 for CA and RFT power 35W, with an ablation time of 8.6(3.01) min and energy of 9126(2555) J. The follow-up time was 20.65(18.2) months. 11(64.7%) are euthyroid, 4(23.5%) continue treatment with thiamazole. The mean percentage of change of 58.5(17.5), for a final volume of 6.62(9.26) ml (p 0.00) (95%CI4.2,10.73). 4(23.5%) presented pain or hematoma as a complication. The comparative analysis between techniques shows an efficacy of 63.6% vs 66.6% for CA vs RFT, but the follow-up time in these patients has been shorter and the volume reduction shows significant difference towards RFT (p 0.04) Conclusions: PA treatment represents an effective and safe alternative treatment for patients with TA. The greater volume reduction through RFT suggests better efficiency, but it is dependent on the learning curve. Presentation: Monday, July 14, 2025