Significance of hyperechoic marks observed during high-intensity focused ultrasound (HIFU) ablation of benign thyroid nodules

• Published in: European radiology Vol. 28; no. 6; pp. 2675 - 2681
• Main Authors: Lang, Brian H.H., Woo, Yu-Cho, Chiu, Keith Wan-Hang
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.06.2018; Springer Nature B.V
• Subjects: Ablation; Benign; Body mass; Diagnostic Radiology; Female; Heart Rate - physiology; High-Intensity Focused Ultrasound Ablation - methods; Humans; Imaging; Internal Medicine; Interventional; Interventional Radiology; Male; Medicine; Medicine & Public Health; Middle Aged; Neuroradiology; Nodules; Patients; Radiology; Regression analysis; Retrospective Studies; Shrinkage; Success; Thyroid; Thyroid gland; Thyroid Nodule - pathology; Thyroid Nodule - surgery; Treatment Outcome; Ultrasonography; Ultrasound; High-intensity focused ultrasound ablation; Interventional ultrasonography; Induced hyperthermia; Nodular goitre; Ablation techniques
• ISSN: 0938-7994; 1432-1084
• DOI: 10.1007/s00330-017-5207-z

Objective To examine the association between the appearance of hyperechoic marks (HEMs) during high-intensity focused ultrasound (HIFU) ablation of benign thyroid nodules and nodule shrinkage at 6 months. Methods One hundred and thirty-six patients who underwent HIFU for benign thyroid nodule were analysed. An independent person carefully examined the B-mode ultrasonography screen for the appearance of HEMs after each pulse. The proportion of HEMs (%) was calculated by: [(Number of pulses that resulted in HEMs) / (Total number of pulses given per treatment) × 100] while the nodule shrinkage was measured by volume reduction ratio (VRR) = [Baseline volume–volume at 6 months]/[Baseline volume] * 100. Treatment success was defined as VRR ≥ 50 %. Results Patients with HEMs (n=91) had significantly greater 6-month VRR than those without HEMs (n=45) (65.76 % vs. 36.76 %, p<0.001). By regression analysis, after adjusting for age and energy per pulse, smaller nodule volume at baseline (OR 1.143, 95 % CI 1.038–1.256, p=0.006) and appearance of HEMs (OR 275.44, 95 % CI 26.63–2848.98, p<0.001) were independent predictors for treatment success. Conclusions The appearance of HEMs during treatment was an independent determinant of treatment success following single-session HIFU ablation of benign thyroid nodule. Key Points • HIFU is a safe and effective treatment for benign thyroid nodules. • Lower BMI and greater applied power increase likelihood of hyperechoic marks. • The appearance of hyperechoic marks during HIFU affects subsequent treatment outcome.