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?P?P?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.     

Outcome of uterine artery embolization versus MR-guided high-intensity focused ultrasound treatment for uterine fibroids: Long-term results

Objectives

To compare the long-term outcome after uterine artery embolization (UAE) versus magnetic resonance-guided high-intensity focused ultrasound (MR-g HIFU) for symptomatic uterine fibroids.

Methods

Seventy-seven women (median age, 39.3 years; range, 29.2–52.2 years) with symptomatic uterine fibroids, equally eligible for UAE and MR-g HIFU based on our exclusion criteria underwent treatment (UAE, N = 41; MR-g HIFU, N = 36) from 2002 to 2009 at our institution. Symptom severity (SS) and total health-related quality of life (Total HRQoL) scores were assessed by the uterine fibroid symptom and quality of life (UFS-QoL) questionnaire before treatment and at long-term follow-up after UAE (median 61.9 months) and after MR-g HIFU (median: 60.7 months). Re-intervention rates were assessed for each therapy and compared.

Results

Re-intervention was significantly lower after UAE (12.2%) than after MR-g HIFU (66.7%) at long-term follow-up (p < 0.001). After UAE changes in SS (50 pre-treatment vs. 6.3 post-treatment) and Total HRQoL (57.8 pre-treatment vs. 100 post-treatment) were significantly better than changes in SS (42.2 pre-treatment vs. 26.6 post-treatment) and Total HRQoL score (66.4 pre-treatment vs. 87.9 post-treatment) after MR-g HIFU (p = 0.019 and 0.049 respectively).

Conclusions

Improvement of SS and Total HRQoL scores was significantly better after UAE resulting in a significant lower re-intervention rate compared to MR-g HIFU.     

Thermal ablation of uterine fibroids using MR-guided focused ultrasound-a truly non-invasive treatment modality

Uterine fibroids are a significant source of morbidity for women of reproductive age. Definitive treatment has traditionally been a hysterectomy, but increasingly women are not prepared to undergo such an invasive procedure for a benign and usually self-limiting condition. Although a number of minimally invasive techniques are now available, focused ultrasound has a considerable advantage over them as it is completely non-invasive and does not require an anaesthetic. Improvements in imaging techniques, particularly magnetic resonance imaging (MRI), have enabled the accurate planning, targeting and monitoring of treatments. We review the early experience of focused ultrasound surgery for the treatment of fibroids, and, in particular, the results of the recent phase I, II and III multi-centre clinical trials. These trials and other studies which demonstrate that MR-guided focused ultrasound ablation is feasible, safe and appears to have an efficacy that is comparable with other treatment modalities are described. This technique has the advantages of being non-invasive and being deliverable as an out-patient procedure.     

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/mm². 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/mm²; (3) b?=?400, 600, 800 s/mm²; and (4) b?=?0, 800 s/mm².

Results

Using the lowest b-values (0 and 200 s/mm²), the mean ADC value in the ablated tissue reduced significantly (p?b-values (400, 600, 800 s/mm²), the ADC increased significantly (p?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/mm² 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     

Volumetric feedback ablation of uterine fibroids using magnetic resonance-guided high intensity focused ultrasound therapy

Objective

The purpose of this prospective multicenter study was to assess the safety and technical feasibility of volumetric Magnetic Resonance-guided High Intensity Focused Ultrasound (MR-HIFU) ablation for treatment of patients with symptomatic uterine fibroids.

Methods

Thirty-three patients with 36 fibroids were treated with volumetric MR-HIFU ablation. Treatment capability and technical feasibility were assessed by comparison of the Non-Perfused Volumes (NPVs) with MR thermal dose predicted treatment volumes. Safety was determined by evaluation of complications or adverse events and unintended lesions. Secondary endpoints were pain and discomfort scores, recovery time and length of hospital stay.

Results

The mean NPV calculated as a percentage of the total fibroid volume was 21.7%. Correlation between the predicted treatment volumes and NPVs was found to be very strong, with a correlation coefficient r of 0.87. All patients tolerated the treatment well and were treated on an outpatient basis. No serious adverse events were reported and recovery time to normal activities was 2.3?±?1.8?days.

Conclusion

This prospective multicenter study proved that volumetric MR-HIFU is safe and technically feasible for the treatment of symptomatic uterine fibroids.

Key Points

? Magnetic-resonance-guided high intensity focused ultrasound allows non-invasive treatment of uterine fibroids. ? Volumetric feedback ablation is a novel technology that allows larger treatment volumes ? MR-guided ultrasound ablation of uterine fibroids appears safe using volumetric feedback     

磁共振引导高强度聚焦超声完全消融子宫肌瘤:可行性、安全性和远期疗效

目的 评估MRI引导高强度聚焦超声(MRgHIFU)完全消融子宫肌瘤的可行性、安全性和远期疗效.方法 对43例(平均年龄41.4岁)共51个子宫肌瘤,平均大小为(7.1±1.4)em,均进行一次MRI引导高强度聚焦超声消融术.治疗后即刻MRI增强测量靶肌瘤的体积及其无灌注区的体积,子宫肌瘤无灌注区的完全覆盖靶肌瘤为完全消融.对完全消融的子宫肌瘤在治疗后3个月、6个月、1年、2年和3年通过MRI进行随访复查肌瘤的体积变化;在术前、3、6个月采用UFS-QOL症状评分方法对患者症状评分,并随访3年观察其症状的变化.同时对这些肌瘤的特征、治疗后不良事件、聚焦超声能量及治疗效率等进行了分析.结果 经MRgHIFU治疗后肌瘤平均消融率为84.3％±15.7％(范围33.8％～ 100％),肌瘤部分消融(消融率＜90％)、几乎完全消融(消融率为90％～99％)和完全消融的病例分别为23例、10例和10例,平均治疗时间为(2.2±0.8)h(范围1.0 ～ 4.3 h),治疗后均未发生并发症.10例13个完全消融的肌瘤术前MRI均为T2低信号表现而其血供类型不同;超声治疗的能效因子(EEF)为:(3.6±2.1)J/mm3(0.7 ～ 6.8 J/mm3).治疗后3、6个月症状严重程度评分(SSS)分别为从术前的33.9±7.1下降至16.6±9.0和8.1±3.4(P＜ 0.01),1年或2年后10例患者的症状完全消失.治疗后3、6个月和3年肌瘤体积分别缩小39.5％±10.2％、59.1％±9.0％和93.3％±3.1％(P＜0.01).治疗后3年随访肌瘤均未出现复发.结论 MRI引导高强度聚焦超声完全消融子宫肌瘤是可行的、安全的和有效的,MRI T2WI低信号肌瘤可在治疗后取得完全消融.     

MRI导航和温度监控下高强度聚焦超声治疗子宫肌瘤

目的 评价高强度聚焦超声(HIFU)在MR导航定位和靶区焦域温度监控下治疗子宫肌瘤的可行性和疗效.方法 采用西门子1.5 T Avanto TIM MR导航和温度监控JM-HIFU进行HIFU治疗52例子宫肌瘤共61个肌瘤.肌瘤大小(6.1±2.1)cm,其中浆膜下10枚、肌壁间46枚和黏膜下5枚.治疗前、后采用增强扫描MRI检查,测量肌瘤体积、消融坏死区域大小占肌瘤体积的比率,并记录治疗时间和超声释放剂量.治疗后3个月MRI检查观察肌瘤的缩小情况;同时观察和评估其并发症及不良反应事件发生,并对治疗前后患者症状变化进行评分.结果 MR导航HIFU(MRgHIFU)治疗前和治疗后3个月肌瘤平均体积分别为(113.3±87.7)cm3和(58.1±45.0)cm3,肌瘤体积平均缩小(48.7±16.4)%(P＜0.05);每个肌瘤被消融区域占整个肌瘤体积平均为(78.8±18.8)%(51%～100%);聚焦超声治疗时间(19.8±8.8)min,治疗所用的超声热剂量为(7.1±6.7)焦耳/mm3.患者症状平均总分治疗前、后从(24.7±4.8)下降至(16.7±3.2)分(P＜0.05),除1例术中出现腹壁皮下轻度烫伤,余无并发症及不良反应事件.结论 MRgHIFU治疗子宫肌瘤是一种可行、安全、有效的无创治疗方法,而且单次热消融可达到肌瘤大部分甚至完全凝固性坏死,并使其短期内缩小的治疗效果.     

Magnetic resonance imaging-guided focused ultrasound ablation of uterine fibroids: early clinical experience

PURPOSE: The aim of this study was to assess the feasibility and effectiveness of magnetic resonance (MRI)-guided focused ultrasound (MRIgFUS) ablation for uterine fibroids and to identify the candidates for this treatment. MATERIALS AND METHODS: A total of 48 patients with a symptomatic uterine fibroid underwent MRIgFUS. The percent ablation volume was calculated, and the patients' characteristics and the MR imaging features of the fibroids that might predict the effect of this treatment were assessed. Changes in the symptoms related to the uterine fibroid were assessed at 6 and 12 months. RESULTS: The planned target zone were successfully treated in 32 patients with bulk-related and menstrual symptoms but unsuccessfully treated in the remaining 16 patients. These 16 patients were obese or their uterine fibroid showed heterogeneous high signal intensity on T2-weighted images. The 32 successfully treated patients were followed up for 6 months. At the 6-month follow-up, bulk-related and menstrual symptoms were diminished in 60% and 51% of patients, respectively. Among them, 17 patients were followed up for 12 months, and 9 of them who showed alleviation of bulk-related symptoms at 6 months had further improvement. The mean percent ablation volume of those nine patients was 51%. In 5 (33%) of the 15 patients with alleviation of menstrual symptoms at 6 months, the symptoms became worse at 12 months. There was a significant difference in the mean percent ablation volume between patients with alleviation of menstrual symptoms and those without (54% vs. 37%; P = 0.03). CONCLUSION: MRIgFUS ablation is a safe, effective treatment for nonobese patients with symptomatic fibroids that show low signal intensity on T2-weighted images. Ablation of more than 50% of the fibroid volume may be needed with a short-term follow-up.     

扶正消瘤方联合高强度聚焦超声治疗子宫肌瘤的疗效分析

目的：评估扶正消瘤方联合高强度聚焦超声（HIFU）治疗子宫肌瘤的疗效价值。方法：选取98例（113个肌瘤）子宫肌瘤患者,随机分为实验组49例（57个肌瘤）及对照组49例（56个肌瘤）。实验组采用HIFU消融治疗联合扶正消瘤方口服3个月;对照组仅采用HIFU消融治疗。HIFU治疗后6个月行超声造影对2组疗效进行评价。结果：HIFU治疗后6个月,实验组肌瘤体积缩小率明显比对照组高（P<0.05）;实验组治疗显效率（91.23%）,明显高于对照组（64.29%）（P<0.05）。结论：扶正消瘤方联合HIFU治疗子宫肌瘤,结合超声造影技术实时动态评估,临床效果显著。     

超声引导下的高强度聚焦超声治疗黏膜下肌瘤的安全性和有效性

目的评价超声引导下的高强度聚焦超声消融治疗黏膜下肌瘤的安全性和有效性。材料与方法共76名妇女患78个子宫黏膜下肌瘤(68个Ⅱ型,10个Ⅰ型)接受了超声引导下的高强度聚焦超声的消融治疗。治疗前子宫肌瘤的直径为2.4～13.5cm,平均(5.7±2.3)cm。使用420～520W的输出功率对子宫肌瘤进行消融治疗。在随访过程中,采用对比增强MRI和(或)对比增强超声对被消融后子宫肌瘤的体积萎缩情况进行连续观察。使用症状严重程度的问卷评分对症状变化进行评估。结果所有病人对高强度聚焦超声消融治疗耐受性良好。没有出现严重的并发症。对比增强超声检查中,平均无灌注的消融率为(80±12)%。随访期间,消融后的肌瘤明显萎缩,症状明显缓解。没有病人在治疗后出现闭经。在消融治疗后,58%(44/76)的病人出现阴道排出坏死组织,这个现象在2～4个月经周期后消失。4例病人由于残余肌瘤增大而再次接受消融治疗。结论超声引导下的高强度聚焦超声消融术是一种治疗黏膜下肌瘤的安全有效的方法,但对生育的影响还需要进一步的研究。     

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 cm³. Mean fibroid volume was 353 ± 269 cm³ at baseline, which decreased to 271 ± 225 cm³ 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.     

Transrectal high-intensity focused ultrasound ablation of prostate cancer: Effective treatment requiring accurate imaging

Transrectal HIFU ablation has become a reasonable option for the treatment of localized prostate cancer in non-surgical patients, with 5-year disease-free survival similar to that of radiation therapy. It is also a promising salvage therapy of local recurrence after radiation therapy. These favourable results are partly due to recent improvements in prostate cancer imaging. However, further improvements are needed in patient selection, pre-operative localization of the tumor foci, assessment of the volume treated and early detection of recurrence. A better knowledge of the factors influencing the HIFU-induced tissue destruction and a better pre-operative assessment of them by imaging techniques should improve treatment outcome. Whereas prostate HIFU ablation is currently performed under transrectal ultrasound guidance, MR guidance with real-time operative monitoring of temperature will be available in the near future. If this technique will give better targeting and more uniform tissue destruction, its cost-effectiveness will have to be carefully evaluated. Finally, a recently reported synergistic effect between HIFU ablation and chemotherapy opens possibilities for treatment in high-risk or clinically advanced tumors.     

Proton resonance frequency shift-weighted imaging for monitoring MR-guided high-intensity focused ultrasound transmissions

Purpose:

To combine temperature‐related information of phase images and magnitude images acquired from an MR spoiled gradient echo sequence using a postprocessing method referred to as PRF‐shift‐weighted imaging (PRFSWI).

Materials and Methods:

Phase images are capable of detecting shifts in proton resonance frequency (PRF) caused by local changes in temperature. Magnitude images provide anatomical information for treatment planning and positioning as well as temperature‐related contrast. We used PRFSWI to produce a phase‐mask and performed multiplication on the magnitude image to increase temperature‐related contrast.

Results:

Through MRI‐guided focused ultrasound (MRIgFUS) experiments (both ex vivo and in vivo), we determined that PRFSWI is capable of enhancing the contrast of a heated area even in the initial stages of transmitting high‐intensity focused ultrasound energy.

Conclusion:

The PRFSWI images are sensitive to changes in temperature and display the heated spot directly in the magnitude images. Although the images do not provide quantitative data related to temperature, this method could be used as a complement to the phase temperature mapping method in the real‐time monitoring of MRIgFUS experiments. J. Magn. Reson. Imaging 2011;33:1474–1481. © 2011 Wiley‐Liss, Inc.     

Extracorporeal liver ablation using sonography-guided high-intensity focused ultrasound.

RATIONALE AND OBJECTIVES. High-intensity focused ultrasound (HIFU) is the only radiation beam that can remotely destroy deep-seated tissue targets without causing damage to the intervening tissues. This study evaluates the ability of sonography-guided HIFU to extracorporeally induce liver ablation in a rabbit model. METHODS. Under sonographic guidance, the HIFU beam was transcutaneously focused at the target tissue in the liver through a subcostal approach. A computer controlled the HIFU exposure and transducer movement to destroy a preselected tissue volume. Simultaneous sonography monitored the tissue response. Ten insonated rabbits were killed from days 0 to 10, and the liver and intervening tissues were examined histologically. RESULTS. A sharply demarcated sonolesion of coagulation necrosis was produced in the liver in 9 of 10 animals. No damage was found in the intervening tissues (n = 6) when adequate acoustic coupling and proper beam path was applied. CONCLUSION. Sonography-guided HIFU might be a potential new modality for extracorporeal inducement of liver cancer ablation without resorting to laparatomy.