Safety and Therapeutic Efficacy of Complete or Near-Complete Ablation of Symptomatic Uterine Fibroid Tumors by MR Imaging-Guided High-Intensity Focused US Therapy

Purpose: To evaluate the safety and therapeutic efficacy of magnetic resonance (MR) imaging-guided high-intensity focused ultrasound (US) ablation of symptomatic uterine fibroid tumors with an immediate nonperfused volume (NPV) ratio of 80% or more. Materials and Methods: A total of 79 women with 117 uterine tumors were treated with MR-guided high-intensity focused US ablation. Immediate NPV, complications, and therapeutic efficacy (tumor volume reduction ratio and symptom severity score [SSS] decrease at 3-mo follow-up) were retrospectively assessed. Statistical comparisons of the frequency of complications and therapeutic efficacy were performed between patients with NPV ratios of at least 80% and less than 80%. Results: Technical success was achieved in 93.7% of cases (n = 74) of cases, and the immediate NPV ratio was 62.7% +/- 25.5. Twenty-four patients exhibited an NPV ratio of at least 80% (89.7% +/- 5.8), and 50 patients showed an NPV ratio of less than 80% (49.8% +/- 20.7). All complications were minor in severity, and the incidences were not significantly different between groups (P > .05). The 3-month volume reduction ratio was significantly greater in patients with at NPV ratio of at least 80% (0.43 +/- 0.17) than in those with an NPV ratio of less than 80% (0.20 +/- 0.26; P = .002), although the decreases in SSS were not significantly different (20.9 +/- 19.6 vs 12.1 +/- 10.1; P = .097). Conclusions: In MR-guided high-intensity focused US ablation of symptomatic uterine fibroid tumors, achievement of an immediate NPV ratio of at least 80% is safe, with greater tumor volume shrinkage compared with cases with a lower NPV ratio.