Clinical outcomes following percutaneous magnetic resonance image guided laser ablation of symptomatic uterine fibroids

Comparison of thermal ablative methods and myomectomy for the treatment of fibroids: a systematic review and meta-analysis

OBJECTIVE

To examine the effectiveness and safety of thermal ablative methods and myomectomy for the treatment of uterine fibroids.

MATERIALS AND METHODS

We searched EMBASE, PubMed, the Cochrane Central Register of Controlled Trials, Scopus, CINAHL, ClinicalTrials.gov and Web of Science databases through April 2021. Clinical trials comparing the thermal ablative methods and myomectomy for the treatment of uterine fibroids were included.

RESULTS

Thirteen studies including 4205 patients were eligible. The thermal ablative treatment group was associated with less major adverse events (only ultrasound guided high-intensity focused ultrasound) (RR, 0.111 [95% CI, 0.070-0.175], p=.0), shorter duration of hospital stays in observational studies (-0.1497 day, [95% CI, -1.593 to -0.321], p=.0) and in randomized controlled trials (RCTs) (-0.844 day, [95% CI, -0.1.142 to -0.546], p=.0), higher uterine fibroid symptom (UFS) score after operation (0.252 [95% CI, 0.165-0.339]; p=.0), transformed symptom severity (tSS) score after operation (0.515 [95% CI, 0.355-0.674]; p=.0) and quality of life (QoL) score after operation (0.188 [95% CI, 0.093-0.283]; p=.0) in comparison with myomectomy group. No statistically significant difference was found between the thermal ablative treatment group and myomectomy group with respect to reintervention rate and pregnancy rate.

CONCLUSION

The current data available demonstrate that thermal ablative methods were not inferior to myomectomy in the treatment of uterine fibroids. The findings in this study need to be further confirmed by large RCTs.

Temperature-dependent dielectric properties of human uterine fibroids over microwave frequencies

Microwave ablation is under investigation as a minimally-invasive treatment for uterine fibroids. Computational models play a vital role in the development, evaluation and characterization of candidate ablation devices. The temperature-dependent dielectric properties of fibroid tissue are essential for accurate computational modeling.Objective:To measure the broadband temperature-dependent dielectric properties of uterine fibroids excised during hysterectomy procedures.Methods: The open-ended coaxial probe method was employed for measuring the broadband dielectric properties of freshly excised human uterine fibroid samples (n = 6) obtained from an IRB-approved tissue bank. The dielectric properties (relative permittivity,ε_r, and effective electrical conductivity,σ_eff) were evaluated at temperatures ranging from 23 °C-150 °C, over the frequency range of 0.5-6 GHz. Linear piecewise parametrization with respect to temperature and quadratic parametrization with respect to frequency was applied to characterize broadband temperature-dependent dielectric properties of fibroid tissue.Results: The baseline room temperature values ofε_rvary from 57.5 ± 5.29 to 44.5 ± 5.77 units andσ_effchanges from 0.91 ± 0.19 to 6.02 ± 0.7 S m^-1over the frequency range of 0.5-6 GHz. At temperatures close to the water vaporization point,ε_r, drops considerably i.e. to 12%-14% of its baseline value for all measured frequencies.σ_effvalues initially rise till 98 °C and then fall to 11%-13% of their baseline values at 125 °C for frequencies ≤2.45 GHz. Theσ_efffollows a decreasing trend for frequencies >2.45 GHz and drops to ∼6 % of their baseline room temperature values.Conclusion:The temperature dependent dielectric properties of uterine fibroid tissues over microwave frequency range are reported for the first time in this study. Parametric models of uterine fibroid dielectric properties are also presented for incorporation within computational models of microwave ablation of fibroids.

A Systematic Review of Minimally Invasive Treatments for Uterine Fibroid-Related Bleeding

Newer minimally invasive techniques provide treatment options for symptomatic uterine fibroids while allowing uterus preservation. The objective of this review was to analyze the efficacy of uterine-preserving, minimally invasive treatment modalities in reducing fibroid-related bleeding. A comprehensive search was conducted of PubMed, Embase, PsycINFO, ClinicalTrials.gov, Scopus, and Cochrane Library databases from inception to July 2020. English-language publications that evaluated premenopausal women with fibroid-related bleeding symptoms before and after treatment were considered. Randomized controlled trials were assessed for bias with the established Cochrane Risk of Bias Tool 2.0 and observational studies were assessed for quality under the New Castle-Ottawa Scale guidelines. Eighty-four studies were included in the review, including 10 randomized controlled trials and 74 observational studies. Six studies on myomectomy demonstrated overall bleeding symptom improvement in up to 95.9% of patients, though there was no significant difference between mode of myomectomy. Forty-one studies on uterine artery embolization reported significant reduction of fibroid-related bleeding, with symptomatic improvement in 79 to 98.5% of patients. Three studies suggested that embolization may be superior to myomectomy in reducing fibroid-related bleeding. Six studies reported that laparoscopic uterine artery occlusion combined with myomectomy led to greater reduction of bleeding than myomectomy alone. Fifteen studies demonstrated significantly reduced bleeding severity after radiofrequency ablation (RFA). Additional research is needed to establish the superiority of these modalities over one another. Long-term evidence is limited in current literature for magnetic resonance-guided focused ultrasound surgery, cryomyolysis, microwave ablation, and laser ablation.

Thermal ablative treatment of uterine fibroids

In addition to surgical methods of treating uterine fibroids, numerous non-invasive treatments have been developed. Many of these involve the use of hyperthermia, the heating of tissue by a variety of methods. These include the use of lasers, radiofrequency, microwave energy and high intensity focused ultrasound, guided by both ultrasound and magnetic resonance imaging. In this review we examine the technology behind these treatment modalities and review the current evidence for their use.

Leiomyoma cutis: a focused review on presentation, management, and association with malignancy

Cutaneous leiomyomas (CLs) are rare, sporadic, or inherited tumors of smooth muscle origin associated with various disorders. Hereditary leiomyomatosis and renal cell cancer (HLRCC) is the primary tumor predisposition syndrome associated with inherited CLs, affecting 180 families worldwide, with significant mortality. CLs are subdivided into piloleiomyomas, genital leiomyomas, and angioleiomyomas based on their smooth muscle of origin, as well as their clinicopathologic features. Piloleiomyomas, derived from arrector pili muscle, are solitary or multiple firm papulonodules located typically on the extremities and trunk; genital leiomyomas, derived from dartoic, vulvar, or mammary smooth muscle, are solitary papulonodules or pedunculated papules located on the scrotum, vulva, or nipple; and angioleiomyomas, which include solid, cavernous, or venous subtypes, are derived from the tunica media of small arteries and veins and typically present on the extremities. Partial/excisional biopsy is required for diagnosing all CLs. Histology shows interlacing fascicles of spindle cells with moderate amounts of eosinophilic cytoplasm and a blunt-ended, elongated nucleus with perinuclear halos. Surgical excision is curative for CLs, with other management options including medical or destructive therapy; active surveillance is advised to monitor HLRCC-associated neoplasms, with pharmacological therapies under active research.

[Myomas management, alternatives to hysterectomy and myomectomy: what can we propose?]

Second generation endometrial ablation techniques must be used preferably as they present less complications than first generation techniques. An efficient contraception is highly recommended after thermal ablation. Myolysis techniques are still investigational, focused ultrasound myolysis MR or ultrasound-guided is accessible to approximately 10% of uterine myomas with 70% of long-term symptom relief. Outcomes of laparoscopic uterine artery occlusion are similar to those of uterine artery embolization but with less long-term durability.

Dealing with uterine fibroids in reproductive medicine

Women who wish to conceive are nowadays more likely to present with uterine fibroids, mainly because of the delay in childbearing in our society. The relationship between uterine fibroids and human reproduction is still controversial and counselling patients might sometimes be challenging. This paper is to assist those involved in the management of patients of reproductive age presenting with uterine fibroids. The interference of fibroids on fertility largely depends on their location. Submucous fibroids interfere with fertility and should be removed in infertile patients, regardless of the size or the presence of symptoms. Intramural fibroids distorting the cavity reduce the chances of conception, while investigations on intramural fibroids not distorting the cavity have so far given controversial results. No evidence supports the systematic removal of subserosal fibroids in asymptomatic, infertile patients. Myomectomy is still the 'gold standard' in fibroid treatment for fertility-wishing patients. In experienced hands, hysteroscopic myomectomy is minimally invasive, safe, and effective. Abdominal and laparoscopic myomectomy might be challenging, but potential risks could be reduced by new strategies and techniques.

Safety and efficacy of US-guided high-intensity focused ultrasound for treatment of submucosal fibroids

OBJECTIVES

To evaluate the safety and efficacy of US-guided high-intensity focused ultrasound (HIFU) ablation for the treatment of submucosal fibroids

METHODS

A total of 76 women with 78 submucosal uterine fibroids (68 type II fibroids, 10 type I fibroids) underwent US-guided HIFU ablation. The pretreatment fibroid diameter ranged from 2.4 to 13.5 cm (mean 5.7 ± 2.3 cm). The fibroids were ablated using a power output of 420-520 W. During follow-up, the volume shrinkage of the ablated fibroids was continuously observed on contrast-enhanced MR and/or contrast-enhanced ultrasound (CEUS). The change of symptoms was evaluated by using the symptom severity score questionnaire.

RESULTS

HIFU ablation was well tolerated in all patients. No major complications occurred. The mean nonperfused ablation ratio was 80 ± 12 % on CEUS. During follow-up, the ablated fibroids shrank significantly over time. The symptoms were alleviated significantly. No patients had amenorrhoea after treatment. Vaginal expulsion of necrotic tissue was seen in 58 % (44/76) of patients after HIFU ablation which disappeared after 2-4 menstrual cycles. Four patients received repeated HIFU ablation for enlarged residual fibroids.

CONCLUSIONS

US-guided HIFU ablation may be a safe and effective treatment for submucosal fibroids. Further studies are warranted to observe its influence on fertility.

KEY POINTS

• High-intensity focused ultrasound (HIFU) is a new minimally invasive therapeutic technique. • HIFU ablation may be safe and effective for treatment of submucosal fibroids • Treatment is minimally invasive and repeatable. • Vaginal expulsion of necrotic tissue is common after treatment.

MR-guided high-intensity focused ultrasound treatment for symptomatic uterine leiomyomata: long-term outcomes

RATIONALE AND OBJECTIVES

To evaluate the long-term clinical outcomes of magnetic resonance--guided high-intensity focused ultrasound (MR-g HIFU) treatments for symptomatic uterine leiomyomata.

MATERIALS AND METHODS

Patients were recruited for a prospective study for MR-g HIFU treatments of symptomatic leiomyomata, with up to 3-year follow-up. The study was approved by the institutional review board and was Health Insurance Portability and Accountability Act--compliant. Clinical assessments were obtained at 3 months, 6 months, and 1, 2, and 3 years after MR-g HIFU, as well as uterine fibroid symptom severity scores (SSS) and health-related quality of life questionnaires (UFS-QOL). MR imaging was performed at each follow-up to assess the efficacy of the treatment at 6 months, 1 year, 2 years, and 3 years.

RESULTS

Fifty-one leiomyomata in 40 patients were treated. All patients were treated within the US Food and Drug Administration guidelines with leiomyomata localized on MR and treated with sonication. The mean baseline volume of treated leiomyomata was 336.9 cm(3). The mean improvement scores for transformed SSS was 47.8 (P < .001) and for tUFS-QOL was 39.8 (P < .001) at 3 years. The mean volume decrease in treated leiomyomata was 32.0% (P < .001), and, in the uterus, the volume decrease was 27.7% (P < .001) at 3 years. There were no long-term complications.

CONCLUSIONS

Long-term follow-up data from MR-g HIFU treatments show sustained symptomatic relief among enrolled patients. Although the results are preliminary, MR-g HIFU for the treatment of uterine leiomyomata may result in acceptable long-term outcomes at 3 years.

Midterm outcome of ultrasound-guided alcohol gel sclerotherapy for symptomatic leiomyoma

OBJECTIVE

The purpose of this study was to describe the outcome of ultrasound-guided ethanol gel sclerotherapy of myomatous nodules 1 to 18 months after treatment.

METHODS

A total of 118 consecutive patients with a diagnosis of symptomatic leiomyomas referred for ethanol gel sclerotherapy were studied between November 2005 and July 2007. Clinical (self-administered symptom questionnaire) and ultrasound follow-ups were done 1 to 2, 6 to 8, and 12 to 18 months after the procedure.

RESULTS

The mean baseline volumes +/- SD were 223.3 +/- 158.3 cm(3) for the uterus and 68.4 +/- 110.5 cm(3) for the dominant fibroid. The most common adverse reaction in the immediate postoperative period was pelvic pain in 27.1% of the patients, but 58.4% had no reactions. After 12 months, a 29.5% reduction in uterine volume was observed in 64.7% of the patients. A 55.5% reduction in dominant fibroid volume was observed in 82.8% of the patients. Pelvic pain improved in 29.8% of the sample, dysmenorrhea in 51.7%, and menstrual flow in 39%. Most patients (77%) reported being satisfied or very satisfied with the treatment.

CONCLUSIONS

The results suggest that ethanol gel sclerotherapy is a safe, conservative alternative for treating symptomatic uterine leiomyomas. Further randomized studies are necessary to determine the suitability and indications of this procedure in comparison to other minimally invasive techniques.

Image-guided thermal therapy of uterine fibroids

Thermal ablation is an established treatment for tumors. The merging of newly developed imaging techniques has allowed precise targeting and real-time thermal mapping. This article provides an overview of the image-guided thermal ablation techniques in the treatment of uterine fibroids. Background on uterine fibroids, including epidemiology, histology, symptoms, imaging findings, and current treatment options, is first outlined. After describing the principle of magnetic resonance thermal imaging, we introduce the applications of image-guided thermal therapies, including laser ablation, radiofrequency ablation, cryotherapy, and in particular, magnetic resonance-guided focused ultrasound surgery, and how they apply to uterine fibroid treatment.

Mid-term outcome of magnetic resonance-guided focused ultrasound surgery for uterine myomas: from six to twelve months after volume reduction

STUDY OBJECTIVE

To clarify the volume change ratio of uterine myomas treated with magnetic resonance-guided focused ultrasound surgery (MRgFUS), in relation to the signal intensity of T(2)-weighted magnetic resonance (MR) images.

DESIGN

Prospective study (Canadian Task Force classification II-3).

SETTING

Department of Gynecology, Shinsuma General Hospital, Kobe, Japan.

PATIENTS

Forty-eight myomas in 35 patients were followed up with MR images 6 months after MRgFUS, and 23 myomas in 17 patients were followed up 12 months after MRgFUS. Before treatment, the myomas were classified into 3 types on the basis of the signal intensity of T(2)-weighted MR images as follows: Type 1, low intensity; type 2, intermediate intensity; type 3, high intensity.

INTERVENTIONS

Thermal ablation therapy was performed with an MRgFUS system (ExAblate 2000).

MEASUREMENTS AND MAIN RESULTS

MRgFUS produced a greater volume reduction in type 1 and type 2 myomas than in type 3 myomas. Nonperfused areas always diminished in the period after MRgFUS; however, the volume change was affected by the volume change ratio of perfused areas inside the treated myomas.

CONCLUSION

At present, type 3 myomas should be exempted from the application of MRgFUS, because the nonperfused ratio immediately after the procedure was small compared with that in type 1 and type 2 myomas, and the subsequent volume change was unfavorable.

Midterm outcome of radiofrequency thermal ablation for symptomatic uterine myomas

BACKGROUND

Over the past decade an increasing demand for uterine-sparing treatment to manage symptomatic uterine myomas has become apparent in women's health care. A preliminary report showed that radiofrequency ablation (RFA) of uterine fibroids under laparoscopic guidance was a safe and effective minimally invasive approach with encouraging short-term results. The purpose of this study was to evaluate the midterm outcomes of radiofrequency ablation (RFA) of uterine myomas in terms of durability of symptom control and level of health-related quality of life.

METHODS

Consecutive women with symptomatic uterine myomas, no plans for future pregnancy, and who declined hysterectomy were offered RFA ablation of uterine fibroids under laparoscopic guidance. Only 25 patients who completed at least the one-year follow-up assessment were included in the study group. Follow-up evaluations were scheduled at 1, 3, 6, 9, and 12 months and thereafter annually following the procedure. Improvement in myoma-related symptoms and impact on quality of life were assessed using a validated questionnaire (UFS-QOL).

RESULTS

The median number of myomas treated per patient was 1 (range = 1-3). The median baseline volume of the dominant myoma was 76.8 cm3 (range = 14.8-332.8). No intraoperative or postoperative complications occurred. The median follow-up time was 24 months, with nine women completing three years of follow-up. The median reduction in myoma volume was 68.8% and 77.9% at six months and one year, respectively. No further change in fibroid size was observed at two years and three years. One year after the procedure, one woman (4%) underwent hysterectomy for recurrence of fibroid-related symptoms. Quality-of-life measures showed significant and durable improvement compared with baseline.

CONCLUSIONS

RFA of symptomatic fibroids seems a valuable alternative to major surgery, with durable symptom relief for most patients and a low chance of recurrence at midterm.

Ultrasound interstitial thermal therapy (USITT) for the treatment of uterine myomas

Uterine myomas (fibroids) are the most common pelvic tumors occurring in women, and are the leading cause of hysterectomy. Symptoms can be severe, and traditional treatments involve either surgical removal of the uterus (hysterectomy), or the fibroids (myomectomy). Interstitial ultrasound technologies have demonstrated potential for hyperthermia and high temperature thermal therapy in the treatment of benign and malignant tumors. These ultrasound devices offer favorable energy penetration allowing large volumes of tissue to be treated in short periods of time, as well as axial and angular control of heating to conform thermal treatment to a targeted tissue, while protecting surrounding tissues from thermal damage. The goal of this project is to evaluate interstitial ultrasound for controlled thermal coagulation of fibroids. Multi-element applicators were fabricated using tubular transducers, some of which were sectored to produce 180° directional heating patterns, and integrated with water cooling. Human uterine fibroids were obtained after routine myomectomies, and instrumented with thermocouples spaced at 0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 cm from the applicator. Power levels ranging from 8-15 W per element were applied for up to 15 minute heating periods. Results demonstrated that therapeutic temperatures >50° C and cytotoxic thermal doses (t43) extended beyond 2 cm radially from the applicator (>4 cm diameter). It is anticipated that this system will make a significant contribution toward the treatment of uterine fibroids.

Percutaneous Image-guided Radiofrequency Thermal Ablation for Large Symptomatic Uterine Leiomyomata after Uterine Artery Embolization: A Feasibility and Safety Study

PURPOSE

To evaluate the feasibility and safety of percutaneous image-guided radiofrequency ablation (RFA) performed with moderate sedation for large symptomatic uterine leiomyomata.

MATERIALS AND METHODS

Women with large (>5 cm in diameter) symptomatic subserosal and/or intramural uterine leiomyoma were recruited for a prospective study. Patients underwent percutaneous RFA following UAE. RFA using 5 cm treatment diameter expandable needle electrodes connected to a 460 kHz monopolar RF generator, which was performed with a target temperature and power set at 85 degrees C and 150 watts respectively, with a target temperature ablation time of 10 minutes. Patients were assessed for complications in perioperative and post-procedure periods at 24 hours and 1 month, and for symptom improvements at 6 months.

RESULTS

Thirty-five patients (mean 43.8 years +/- 6.2) were recruited. RFA targeting ablation size and temperature was achieved in 97% of the patients (34/35). There were no immediate percutaneous RFA-related complications. There was a self-limiting delayed drainage via the transabdominal RFA access track in one patient (2.9%), a urinary tract infection in one patient (2.9%) and post-embolization/post-ablation symptoms in three patients (8.6%). The mean transformed symptom severity score (SSS) as a part of the uterine fibroid symptom and quality of life (UFS-QOL) assessment shows that the improvements at 1 month were 24.3 points ( P < 0.001) and at 6 months were 40.4 points ( P < 0.001). Mean volume reduction of leiomyomata was 286.8 cm(3) or 56.5% ( P = 0.0015).

CONCLUSIONS

Percutaneous image-guided RFA as adjunctive to UAE under moderate sedation is feasible, and appears safe without significant morbidity in the treatment of large uterine leiomyomata.

Magnetic resonance-guided percutaneous cryoablation of uterine fibroids: early clinical experiences

PURPOSE

Uterine fibroids (leiomyomas) are the most common tumors of the uterus. The present study evaluated the feasibility and effectiveness of magnetic resonance (MR)-guided percutaneous cryoablation for uterine fibroids as a minimally invasive treatment alternative.

METHODS

From August 2001 to June 2002, MR-guided percutaneous cryoablation was performed on seven uterine fibroids in 6 patients who displayed clinical symptoms related to tumors. Using a horizontal-type open MR system, cryoablation probes were percutaneously placed in fibroids. Fibroids were ablated, and the site and size of ice balls were monitored on MR imaging. Postoperatively, patients completed a questionnaire to assess changes in presenting clinical symptoms, and MR images were obtained for all patients at follow-up. Changes in clinical symptoms and tumor volume were evaluated in each patient.

RESULTS

All treated patients showed reductions in tumor size. Mean volume reduction rate was 40.3% at 6 weeks postoperatively, and 79.4% at 9-12 months. All patients reported fever after treatment. Surgical drainage was required for abscess in the probe channel in one patient, and transient liver damage occurred in another. Subjective symptoms improved in all patients except one who had multiple tumors, and no patient complained of new symptoms after cryoablation during follow-up.

CONCLUSION

MR-guided percutaneous cryoablation represents a feasible and effective treatment for uterine fibroids.

Does the phase of menstrual cycle affect MR-guided focused ultrasound surgery of uterine leiomyomas?

PURPOSE

To determine whether the phase of menstrual cycle at the time of MR-guided focused ultrasound surgery (MRgFUS) treatment for uterine leiomyomas affects treatment outcome.

METHODS

We enrolled all patients participating in a prospective phase III clinical trial from our center who completed 6 months of clinical and imaging follow-up. Patients with irregular cycles and those on oral contraceptives were excluded. Data prospectively documenting the date of the last menstrual period (LMP) at the time of treatment, length and duration of cycle, and raw symptom severity score (SSS) from the Uterine Fibroid Symptom and Quality of Life questionnaire, at baseline and 6 months were collected. Proliferative phase patients were determined retrospectively as those who were treated within less than 14 days from LMP; secretory phase patients were classified as those who were treated greater than 14 days from LMP.

RESULTS

A total of 58 patients were enrolled. There was no significant difference in the mean SSS at baseline and mean SSS at 6 months between patients treated in the proliferative versus secretory phase of the cycle. No significant difference in the SSS change from baseline to 6 months was seen between the two groups.

CONCLUSIONS

Menstrual cycle phase does not influence MRgFUS treatment outcome. Symptomatic improvement occurs with treatment during either phase of the menstrual cycle. Thus, the scheduling of MRgFUS treatment need not be based upon the phase of the menstrual cycle.

Future directions in myoma research

This article highlights our current knowledge of fibroids and addresses future directions for fibroid research and treatment over the next decade. The available data on cytogenetics are discussed, in addition to discoveries into signaling pathways and second messenger molecules in leiomyomas. Current medical management, surgical trends and the barriers to transition to minimally invasive procedures are summarized. Innovations in genetic diagnosis and interventional radiologic-aided therapies may revolutionize therapy for certain populations of patients who have fibroids. From tissue-specific medical management, to minimally invasive surgical techniques, to pharmacogenetics, the current directions of fibroid research are leading us to an exciting new frontier.

New Treatments for Uterine Fibroids

Since the introduction of uterine artery embolization as a minimally invasive treatment option for uterine fibroids, there has been a great deal of effort made toward developing other options for these patients. These options approach the problem differently, either with direct targeting of individual fibroids, organ-wide targeting of multiple fibroids, and systemic therapy to address the problem of fibroids using a hormonal approach. This review will focus on the different techniques and different philosophies that have been applied to the treatment of fibroids during the past decade.

Clinical outcomes of focused ultrasound surgery for the treatment of uterine fibroids

OBJECTIVE

To assess outcomes at 6 and 12 months after magnetic resonance-guided focused ultrasound surgery (MRgFUS) for symptomatic uterine leiomyomas.

DESIGN

Multicenter clinical trial.

SETTING

Academic medical centers.

PATIENT(S)

Premenopausal women with symptomatic uterine leiomyomas and no plans for future pregnancy (n = 109 at 6 months and n = 82 at 12 months).

INTERVENTION(S)

A single treatment session of MRgFUS for uterine fibroids.

MAIN OUTCOME MEASURE(S)

Reduction in fibroid symptoms as measured by the symptom severity score (SSS) of the Uterine Fibroid Quality-of-Life Instrument (UFS-QOL), the only validated measure of leiomyoma symptomatology. A 10-point reduction in the SSS was selected as the targeted improvement.

RESULT(S)

Seventy-one percent of women undergoing MRgFUS reached the targeted symptom reduction at 6 months, and 51% reached this at 12 months. The magnitude of improvement in SSS was greater than predicted, with subjects having a mean decrease of 39% and 36% at 6 and 12 months, respectively. This paralleled the improvement seen using the short form-36 instrument. A modest volume reduction similar in magnitude to the treated volume was seen. The incidence of adverse events was low.

CONCLUSION(S)

MRgFUS treatment results in short-term symptom reduction for women with symptomatic uterine leiomyomas with an excellent safety profile.

Magnetic resonance guidance of thermal ablation

The aim of this study is to describe all aspects of the process of using MR imaging to control thermal ablation procedures and the strengths and weaknesses of the individual thermal ablation modalities in relation to their use in the MR environment. Magnetic resonance thermal sequences, MR scanner configurations, and the different thermal ablation modalities are discussed in the context of how they are commonly used in MR scanners to provide optimal image guidance of therapy. The outcomes of completed research on some of the applications of thermal tissue ablation using MR guidance are described to indicate how these processes may impact patient treatment. At the end of this review, the reader should have an understanding of how MR guidance of thermal ablation may be carried out, in what areas it is currently most used, and were it may develop in the near future.

Real-time magnetic resonance imaging to guide pediatric endovascular procedures

Although x-ray fluoroscopy (XRF) has guided diagnostic and therapeutic transcatheter procedures for decades, certain limitations still exist. XRF still visualizes tissue poorly and relies on projection of shadows that do not convey depth information. Adjunctive echocardiography overcomes some of these limitations but still suffers suboptimal or unreliable imaging windows. Furthermore, ionizing radiation exposure in children imparts a cancer risk. An interventional platform using real-time magnetic resonance imaging (MRI) may offer superior image guidance without radiation. Although there are many remaining challenges, but real-time MRI has the potential to revolutionize transcatheter therapeutics.

Laparoscopic radiofrequency thermal ablation: a new approach to symptomatic uterine myomas

OBJECTIVE

The purpose of this study was to evaluate the feasibility and efficacy of laparoscopic radiofrequency ablation of uterine fibroids.

STUDY DESIGN

Eighteen women with symptomatic intramural uterine myomas underwent radiofrequency ablation under laparoscopic guidance. Postoperative sonographic evaluations of the fibroids size were scheduled at 1, 3, 6 ,9, and 12 months. The impact of myoma-related symptoms on quality of life (QOL) was assessed using a validated questionnaire.

RESULTS

The median number of myomas treated per patient was 1 (1-3). The median baseline volume of the dominant myoma was 67.2 cm 3 (14.8-332.8). No intraoperative or postoperative complications occurred. The median reductions in myomas volume were 41.5%, 59%, and 77% at 1, 3, and 6-months, follow-up evaluation, respectively. No further change in fibroid size was observed at 9 months and 1 year. A significant improvement in the symptoms score and QOL score was observed at 3 and 6 months, follow-up.

CONCLUSION

In this pilot study, laparoscopic radiofrequency ablation successfully reduced fibroid symptoms and fibroid volume in short-term follow-up. Additional studies are needed before its efficacy and safety can be confirmed.

MRI Guidance of Focused Ultrasound Therapy of Uterine Fibroids:Early Results

OBJECTIVE

The purpose of this study was to explore our hypothesis that MRI-guided focused ultrasound therapy for the treatment of uterine fibroids will lead to a significant reduction in symptoms and improvement in quality of life. We describe focused ultrasound therapy applications and the method for monitoring the thermal energy deposited in the fibroids, including the MRI parameters required, in a prospective review of 108 treatments.

MATERIALS AND METHODS

Patients presenting with symptomatic uterine fibroids who attained a minimal symptom severity score and who would otherwise have been offered a hysterectomy were recruited. Thermal lesions were created within target fibroids using an MRI-guided focused ultrasound therapy system. The developing lesion was monitored using real-time MR thermometry, which was used to assess treatment outcome in real time to change treatment parameters and achieve the desired outcome. Fibroid volume, fibroid symptoms, and quality-of-life scores were measured before treatment and 6 months after treatment. Adverse events were actively monitored and recorded.

RESULTS

In this study, 79.3% of women who had been treated reported a significant improvement in their uterine fibroid symptoms on follow-up health-related quality-of-life questionnaires, which supports our hypothesis. The mean reduction in fibroid volume at 6 months was 13.5%, but nonenhancing volume (mean, 51 cm(3)) remained within the treated fibroid at 6 months.

CONCLUSION

This early description of MRI-guided focused ultrasound therapy treatment of fibroids includes follow-up data and shows that, although the volume reduction is moderate, it correlates with treatment volume and the symptomatic response to this treatment is encouraging.

In vivo feasibility of image-guided transvaginal focused ultrasound therapy for the treatment of intracavitary fibroids

OBJECTIVE

To determine the feasibility of uterine tissue ablation in vivo using a transvaginal focused ultrasound applicator guided by ultrasound imaging.

DESIGN

Randomized in vivo animal study.

SETTING

Academic research environment.

ANIMAL(S)

Healthy anesthetized sheep.

INTERVENTION(S)

Uterine treatment location was determined using a computerized targeting system. Five sonications 10 seconds in duration and averaging 2,000 W/cm(2) of focal ultrasound intensity were applied in each animal's uterus. Animals were euthanized either immediately or 2, 7, or 30 days post-treatment.

MAIN OUTCOME MEASURE(S)

Gross and microscopic analysis of the dissected uterus was used to quantitatively and qualitatively determine the ablated region and treatment side effects.

RESULT(S)

Treatments resulted in coagulative necrosis. Histopathological analysis showed that over 7 days, inflammatory cells appeared and smooth muscle bundles regenerated. By day 30, treated tissues healed and scar tissue formed. None of the animals showed abnormal behavior or medical problems. Complications in three animals were damage to the vaginal wall and colon, possibly due to inadequate applicator cooling and an empty bladder during treatment.

CONCLUSION(S)

Transvaginal image-guided high-intensity focused ultrasound has potential for treating uterine fibroids. Further safety testing of this treatment will prepare it for human use.