Sequential high intensity focused ultrasound (HIFU) ablation in the treatment of benign multinodular goitre: an observational retrospective study.

OBJECTIVES: Assessing the efficacy and safety of sequential high-intensity focused ultrasound (HIFU) ablation in a multinodular goitre (MNG) by comparing them with single HIFU ablation. METHODS: One hundred and four (84.6%) patients underwent single ablation of a single nodule (group I), while 19 (15.4%) underwent sequential ablation of two relatively-dominant nodules in a MNG (group II). Extent of shrinkage per nodule [by volume reduction ratio (VRR)], pain scores (by 0-10 visual analogue scale) during and after ablation, and rate of vocal cord palsy (VCP), skin burn and nausea/vomiting were compared between the two groups. RESULTS: All 19 (100%) sequential ablations completed successfully. The 3- and 6-month VRR of each nodule were comparable between the two groups (p > 0.05) and in group II, the 3- and 6-month VRR between the first and second nodules were comparable (p = 0.710 and p = 0.548, respectively). Pain score was significantly higher in group II in the morning after ablation (2.29 vs 1.15, p = 0.047) and nausea/vomiting occurred significantly more frequently in group II (15.8% vs 0.0%, p = 0.012). However, VCP and skin burn were comparable (p > 0.05). CONCLUSIONS: Sequential ablation had comparable efficacy and safety as single ablation. However, patients undergoing sequential ablation are at higher likelihood of pain in the following morning and nausea/vomiting after ablation. KEY POINTS: • Sequential HIFU ablation is well-tolerated in patients with two dominant thyroid nodules • More pain is experienced in the morning following sequential HIFU ablation • More nausea/vomiting is experienced following sequential HIFU ablation.