Clinical transitions amid rapid expansion: a 16-year retrospective analysis of ultrasound-guided high-intensity Focused ultrasound (USgHIFU) for uterine fibroids and adenomyosis in Korea and the necessity for clinical standardization

BACKGROUND: Since its introduction in 2010, Ultrasound-guided High-Intensity Focused Ultrasound (USgHIFU) has rapidly expanded in South Korea, despite the absence of widely accepted standardized clinical protocols. This study evaluated the long-term clinical outcomes of USgHIFU and proposed a standardized MRI-integrated treatment framework incorporating MRI-based planning, treatment verification, and structured follow-up. METHODS: In this retrospective analysis, we included 2,992 patients (1,620 with uterine fibroids and 1,372 with adenomyosis) treated with USgHIFU between 2010 and 2025. Therapeutic efficacy was assessed using non-perfused volume (NPV) ratio, volume reduction rates (VRR), and reintervention rates. Long-term durability, defined as freedom from reintervention, was evaluated using Kaplan-Meier analysis in 476 patients with follow-up durations of 3-9.7 years. RESULTS: Immediate post-treatment contrast-enhanced MRI demonstrated a mean NPV ratio of 86.5 ± 7.2%, with 94.2% of patients achieving an NPV ratio ≥ 80%. At 12 months, the mean VRRs were 77.4% and 61.4% for fibroids and adenomyosis, respectively. In the long-term follow-up subset (n = 476), volume reduction was maintained and then increased, reaching 78.8% for fibroids and 66.3% for adenomyosis at 3-9.7 years. Freedom from reintervention was 99.1% at 12 months, 98.4% at 3 years, and 97.6% at 9.7 years. No major complications were observed after implementation of the standardized treatment framework. CONCLUSION: Standardized USgHIFU treatment, achieving an NPV ratio ≥ 80%, is associated with sustained long-term clinical outcomes and a favorable safety profile. These findings support the clinical value of a standardized MRI-integrated treatment framework and may contribute to future clinical standardization of USgHIFU practice.