ECE2024 Poster Presentations Thyroid (58 abstracts)
1Italian Auxological Institute San Luca Hospital, Endocrinology, Milano, Italy; 2Mauriziano Umberto Hospital, Torino, Italy
Radiofrequency ablation (RFA) is effective in the treatment of thyroid nodules, leading to a 50-90% reduction with respect to baseline. Current guidelines indicate the need for a benign cytology prior to RFA, though, on the other side, this procedure is also successfully used for the treatment of papillary microcarcinomas. No specific indications are available for nodules with an indeterminate cytology (Bethesda III and IV). Aim of the present study was to evaluate the efficacy of RFA in Bethesda III nodules without genetic alterations as verified by means of a customized panel based on matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and previously set up for the simultaneous identification of 13 known hotspot mutations and six recurrent fusion genes. We treated 33 patients (mean delivered energy 1069±1201 Joules/ml of basal volume) with Bethesda III cytology, EU-TIRADS 3-4, and negative genetic panel. The mean basal nodular volume was 17.3±10.7 ml. Considering the whole series, the mean volume reduction rate (VRR) was 36.8±16.5% at 1 month, 59.9±15.5% at 6 months and 62±15.7% at 1-year follow-up. The sub-analysis done in patients with 1 and 2 years follow up data available, confirmed a progressive nodular volume decrease. At all-time points, the rate of reduction was statistically significant (P<0.0001), without significant correlation between the VRR and the basal volume. Neither cytological changes nor complications were observed after the procedure. In conclusion, we show for the first time that one RFA session is extremely effective in the volume reduction of Bethesda III nodules whose very low risk of malignancy has been established on the bases of the lack of the most common oncogene variations. The procedure is applicable for indeterminate nodules of any size, treated with an appropriate energy per volume and the volume reduction is maintained at 1-2 years after treatment, but a longer follow up is needed to identify a further reduction or a possible progressive regrowth.