Objective: To explore the curative effect and influencing factors of ultrasound (US)-guided percutaneous laser ablation (PLA) for benign thyroid nodules. Methods: The study included 164 benign thyroid nodules and followed up 2 years after the PLA treatment. Nodule volume and VRR were evaluated before PLA treatment and during follow-up. The factors related to efficacy were evaluated. Results :The volume of benign thyroid nodules after the PLA treatment was significantly reduced after 1

3

6

12，18，24 months

and their nodule VRR was（5.2±71.1）%，（45.5±41.7）%，（70.4±26.3）%，（86.3±16.3）%，（87.8±15.6）%，（89.2±15.1）% respectively. The thyroid nodules were divided into 3 groups according to the cystic portion

significant differences were found in the VRR at 1 and 3 months after PLA ( P＜0.05)

the cystic nodule were the fastest one the lesion shrunk. The nodules with the solid portion were grouped according to the volume of the nodules ( ≤ 5 ml /5～10ml/＞10ml); and significant differences were found in the VRR at 6~24 months after PLA (The VRR of nodules of which the volume ≤ 5 ml was larger). Multiple linear regression analysis showed that initial nodule volume (P<0.001) was the only independent factors predicting final VRR. Conclusions: US-guided PLA is a safe and effective minimally invasive therapy for benign thyroid nodules. The initial volume of the nodules will affect the postoperative VRR.