Volumetric MR-guided high-intensity focused ultrasound versus uterine artery embolisation for treatment of symptomatic uterine fibroids: comparison of symptom improvement and reintervention rates.

PURPOSE: To compare the effectiveness of magnetic resonance-guided high-intensity focused ultrasound (MR-HIFU) with that of uterine artery embolisation (UAE) for treatment of uterine fibroids. METHODS: Between January 2010 and January 2013, 51 women with symptomatic uterine fibroids underwent MR-HIFU. Follow-up and MR imaging were compared to 68 women treated with UAE, who fulfilled eligibility criteria for MR-HIFU - e.g., size (≤ 12 cm) and number (≤ 5) of fibroids. We compared median symptom severity (tSSS), total health-realted quality of life (HRQoL) scores, and reintervention rates. The adjusted effect on symptom relief and HRQoL improvement was calculated using multivariable linear regression. Cox regression was applied to calculate the adjusted risk of reintervention between both treatments. RESULTS: Median tSSS improved significantly from baseline to three-month follow-up (P < 0.001) for both MR-HIFU (53.1 (IQR [40.6-68.8]) to 34.4 (IQR [21.9-46.9]) and UAE (65.3 (IQR [56.3-74.2]) to 21.9 (IQR [9.4-34.4]). In addition, significantly better HRQoL scores were observed after three months (P < 0.001). However, in multivariate analysis, UAE had a stronger effect on symptom relief and HRQoL improvement than MR-HIFU (P < 0.001). Patients treated with MR-HIFU had a 7.1 (95 % CI [2.00-25.3]; P = 0.002) times higher risk of reintervention within 12 months (18/51 vs. 3/68). CONCLUSION: Both MR-HIFU and UAE result in significant symptom relief related to uterine fibroids. However, MR-HIFU is associated with a higher risk of reintervention. KEY POINTS: • This study compared outcomes between volumetric MR-HIFU and UAE for uterine fibroids. • Both MR-HIFU and UAE result in significant symptom relief and quality of life improvement. • UAE had a stronger positive effect on the clinical outcomes. • Reintervention rate after MR-HIFU ablation was significantly higher than after UAE.

Diffusion-weighted magnetic resonance imaging using different b-value combinations for the evaluation of treatment results after volumetric MR-guided high-intensity focused ultrasound ablation of uterine fibroids.

OBJECTIVES: To assess the value of diffusion-weighted magnetic resonance imaging (DWI) and apparent diffusion coefficient (ADC) mapping using different b-value combinations for treatment evaluation after magnetic resonance-guided high-intensity focused ultrasound (MR-HIFU) of uterine fibroids. METHODS: Fifty-six patients with 67 uterine fibroids were treated with volumetric MR-HIFU. Pre-treatment and post-treatment images were obtained using contrast-enhanced T1-weighted MRI (CE-T1WI) and DWI using b = 0, 200, 400, 600, 800 s/mm(2). ADC maps were generated using subsets of b-values to investigate the effects of tissue ablation on water diffusion and perfusion in fibroids treated with MR-HIFU. Four combinations of b-values were used: (1) all b-values; (2) b = 0, 200 s/mm(2); (3) b = 400, 600, 800 s/mm(2); and (4) b = 0, 800 s/mm(2). RESULTS: Using the lowest b-values (0 and 200 s/mm(2)), the mean ADC value in the ablated tissue reduced significantly (p < 0.001) compared with baseline. Calculating the ADC value with the highest b-values (400, 600, 800 s/mm(2)), the ADC increased significantly (p < 0.001) post-treatment. ADC maps calculated with the lowest b-values resulted in the best visual agreement of non-perfused fibroid tissue detected on CE images. Other b-value combinations and normal myometrium showed no difference in ADC after MR-HIFU treatment. CONCLUSIONS: A decrease in contrast agent uptake within the ablated region on CE-T1WI was correlated to a significantly decreased ADC when b = 0 and 200 s/mm(2) were used. KEY POINTS: DWI could be useful for treatment evaluation after MR-HIFU of uterine fibroids. The ADC in fibroid tissue is influenced by the choice of b- values. Low b-values seem the best choice to emphasise perfusion effects after MR-HIFU.

Mid-term clinical efficacy of a volumetric magnetic resonance-guided high-intensity focused ultrasound technique for treatment of symptomatic uterine fibroids.

OBJECTIVE: To assess the mid-term efficacy of magnetic resonance-guided high-intensity focused ultrasound (MR-HIFU) using a volumetric ablation technique for treating uterine fibroids. METHODS: Forty-six premenopausal women with 58 symptomatic uterine fibroids were prospectively included for MR-HIFU. After treatment, CE-MRI allowed measurement of the non-perfused volume (NPV) ratio, defined as the non-enhancing part of the fibroid divided by fibroid volume. Clinical symptoms and fibroid size on T2W-MRI were quantified at 3 and 6 months' follow-up. The primary endpoint was a clinically relevant improvement in the transformed Symptom Severity Score (tSSS) of the Uterine Fibroid Symptom and Quality of Life questionnaire, defined as a 10-point reduction. RESULTS: Volumetric ablation resulted in a mean NPV ratio of 0.40 ± 0.22, with a mean NPV of 141 ± 135 cm(3). Mean fibroid volume was 353 ± 269 cm(3) at baseline, which decreased to 271 ± 225 cm(3) at 6 months (P < 0.001), corresponding to a mean volume reduction of 29 % ± 20 %. Clinical follow-up showed that 54 % (25/46) of the patients reported a more than 10-point reduction in the tSSS. Mean tSSS improved from 50.9 ± 18.4 at baseline to 34.7 ± 20.2 after 6 months (P < 0.001). CONCLUSION: Volumetric MR-HIFU is effective for patients with symptomatic uterine fibroids. At 6 months, significant symptom improvement was observed in 54 % of patients. KEY POINTS: • Volumetric MR-guided high-intensity focused ultrasound is a novel ablation technique for leiomyomatosis. • We prospectively evaluated the outcome of volumetric MR-HIFU ablation for symptomatic fibroids. • This study showed that volumetric MR-HIFU results in an effective treatment. • A randomised controlled trial would set this technique in an appropriate context.

Volumetric MR-Guided High-Intensity Focused Ultrasound with Direct Skin Cooling for the Treatment of Symptomatic Uterine Fibroids: Proof-of-Concept Study.

OBJECTIVE: To prospectively assess the safety and technical feasibility of volumetric magnetic resonance-guided high-intensity focused ultrasound (MR-HIFU) ablation with direct skin cooling (DISC) during treatment of uterine fibroids. METHODS: In this proof-of-concept study, eight patients were consecutively selected for clinical MR-HIFU ablation of uterine fibroids with the use of an additional DISC device to maintain a constant temperature (T ≈ 20 °C) at the interface between the HIFU table top and the skin. Technical feasibility was verified by successful completion of MR-HIFU ablation. Contrast-enhanced T1-weighted MRI was used to measure the treatment effect (nonperfused volume (NPV) ratio). Safety was evaluated by recording of adverse events (AEs) within 30 days' follow-up. RESULTS: All MR-HIFU treatments were successfully completed in an outpatient setting. The median NPV ratio was 0.56 (IQR [0.27-0.72]). Immediately after treatment, two patients experienced coldness related discomfort which resolved at the same day. No serious (device-related) AEs were reported. Specifically, no skin burns, cold injuries, or subcutaneous edema were observed. CONCLUSION: This study showed that it is safe and technically feasible to complete a volumetric MR-HIFU ablation with DISC. This technique may reduce the risk of thermal injury to the abdominal wall during MR-HIFU ablation of uterine fibroids. This trial is registered with NTR4189.

Targeted vessel ablation for more efficient magnetic resonance-guided high-intensity focused ultrasound ablation of uterine fibroids.

PURPOSE: To report the first clinical experience with targeted vessel ablation during magnetic resonance-guided high-intensity focused ultrasound (MR-HIFU) treatment of symptomatic uterine fibroids. METHODS: Pretreatment T1-weighted contrast-enhanced magnetic resonance angiography was used to create a detailed map of the uterine arteries and feeding branches to the fibroids. A three-dimensional overlay of the magnetic resonance angiography images was registered on 3D T2-weighted pretreatment imaging data. Treatment was focused primarily on locations where supplying vessels entered the fibroid. Patients were followed 6 months after treatment with a questionnaire to assess symptoms and quality of life (Uterine Fibroid Symptom and Quality of Life) and magnetic resonance imaging to quantify shrinkage of fibroid volumes. RESULTS: In two patients, three fibroids were treated with targeted vessel ablation during MR-HIFU. The treatments resulted in almost total fibroid devascularization with nonperfused volume to total fibroid volume ratios of 84, 68, and 86%, respectively, of treated fibroids. The predicted ablated volumes during MR-HIFU in patients 1 and 2 were 45, 40, and 82 ml, respectively, while the nonperfused volumes determined immediately after treatment were 195, 92, and 190 ml respectively, which is 4.3 (patient 1) and 2.3 (patient 2) times higher than expected based on the thermal dose distribution. Fibroid-related symptoms reduced after treatment, and quality of life improved. Fibroid volume reduction ranged 31-59% at 6 months after treatment. CONCLUSION: Targeted vessel ablation during MR-HIFU allowed nearly complete fibroid ablation in both patients. This technique may enhance the use of MR-HIFU for fibroid treatment in clinical practice.