Application of contrast-enhanced ultrasound in minimally invasive ablation of benign thyroid nodules

Objective:This study aimed to investigate the application value of contrast-enhanced ultrasound(CEUS)before and after minimally invasive ablation procedures for benign thyroid nodule(s)(BTN).Methods:This prospective study included patients with BTNs scheduled to undergo ultrasound-guided minimally invasive ablation treatment.CEUS was performed before and after ablation(at 1 day,and 1,6,and 12 months after ablation).Changes in microvascular perfusion and the volume of BTNs were noted and assessed.Results:Sixty-two patients(62 BTNs),who underwent ablation procedures between June 2016 and August 2020,were included.All lesions were confirmed by biopsy,and histopathological results were obtained before ablation treatment.On preoperative CEUS,the lesions exhibited hyperenhancement(53.23%)or iso-enhancement(46.77%)during the arterial phase,and all lesions exhibited iso-enhancement in the venous and late phases.One day after ablation,none of the BTNs exhibited obvious enhancement on CEUS.One(1.61%)lesion was retreated due to a nodule-like enhancement area detected by CEUS at the 6-month follow-up.The mean nodular volume reduction rate(VRR)at 1,6,and 12 months follow-up demonstrated no significant difference between the two ablation groups(microwave ablation versus radiofrequency ablation).Twelve months after ablation,the mean(±SD)VRR of all BTNs was 60.3±10.3%.Conclusion:CEUS helped guide treatment decisions for BTNs before ablation treatment.Moreover,it could also be used to accurately and noninvasively evaluate treatment efficacy.