Thyroid HIFU 101: Size Matters: Big Nodules are a Problem for HIFU Treatment. One session is not enough.
High-intensity focused ultrasound (HIFU) is a new promising thermal ablation technique for treating benign thyroid nodules. Larger-sized >30 ml nodules has been less well described.
MATERIALS AND METHODS:
3 groups (group I: <10 mL; groups II: 10-30 mL; group III: >30 mL).
73 nodules were treated successfully and followed for ≥6 months. The overall median six-month volume reduction was 68.3% (range 22.77-96.50%).
At six months, group III >30 ml had a significantly less volume shrinkage than group I (48.1% vs. 77.6%; p < 0.001) and group II (48.1% vs. 67.9%; p = 0.002). than in the other two groups (p < 0.001).
Single-session HIFU ablation was highly effective in causing shrinkage of benign thyroid nodules at six months, but the extent of shrinkage for larger-sized nodules (>30 mL) was noticeably less than that of smaller-sized nodules. Both pre-ablation nodule volume and total energy per nodule volume were significant determinants of ablation success.
For larger-sized nodules, additional HIFU treatment three to six months after initial treatment might be preferred.