The preliminary multicenter retrospective study on the efficacy and safety of thermal ablation for follicular thyroid neoplasms ≤ 3 cm.

Objectives: To evaluate the efficacy and safety of thermal ablation (TA) for follicular thyroid neoplasms (FTN) ≤ 3 cm.

Methods: This retrospective multicenter study enrolled 161 patients (131 females; mean age, 46 ± 15 years [range, 11-86]) who underwent TA for FTN ≤ 3 cm between January 2014 and October 2023 from eight centers in China. The median follow-up time was 12 months (IQR, 12-24 months). Based on the maximum diameter (MD) of the nodule, patients were divided into two groups: Group 1 (MD ≤ 2 cm) and Group 2 (2 < MD ≤ 3 cm). Post-ablation assessments encompassed evaluations of tumor size and volume changes, technical success rate, tumor disappearance, disease progression, complications, and risk factors associated with recurrent laryngeal nerve (RLN) injury.

Results: All patients underwent complete ablation in a single session. The technical success rate was 100%. The mean volume reduction rate (VRR) of the ablation zone at 12 months was 78.11%. The VRR at 12 months was higher in Group 1 than that in Group 2 (Median VRR, 93.8% vs. 82.8%; P = 0.019). The complete tumor disappearance rate was 15.5% (25/161). Smaller tumors have a higher tumor disappearance rate (Group 1 vs Group 2 = 27.6% vs. 4.7%; P < 0.001). The disease progression rate was 2.5% (4/161), with no significant difference between Group 1 and Group 2 (P = 0.535). The complication rate was 3.1% (5/161), with no significant difference between Group 1 and Group 2 (P = 0.899). No risk factors were identified for RLN injury.

Conclusions: Thermal ablation is an effective and safe treatment option for patients with FTN ≤ 3 cm.