Magnetic resonance guided focused ultrasound surgery : a novel treatment for uterine fibroids

• Main Author: Zaher, Summia S.
• Other Authors: Bennett, Phillip ; Gedroyc, Wladyslaw ; Regan, Lesley
• Published: Imperial College London 2010
• Subjects: 616.89
• Online Access: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.523255

Uterine fibroids are the most common tumour of the reproductive tract in women of reproductive age. Although they are benign tumours that are often asymptomatic, they may cause debilitating symptoms in many women, such as abnormal uterine bleeding, abdominal pain, increased abdominal girth, urinary frequency, constipation, pregnancy loss, dyspareunia, and in some cases infertility. Several approaches are available for the treatment of uterine fibroids. These include pharmacologic options, such as hormonal therapies and gonadotropinreleasing hormone agonists; surgical approaches, such as hysterectomy, myomectomy; myolysis, laparoscopic uterine artery occlusion, uterine artery embolisation and magnetic resonance imaging-guided focused ultrasound surgery. The choice of approach may be dictated by factors such as the patient’s desire to become pregnant in the future, the importance of uterine preservation, symptom severity, and tumour characteristics. There is however, no widely agreed therapeutic strategy. There is a widespread view that hysterectomy is overused in the UK; the Chief Medical Officer in his annual report ‘On the state of public health’ in 2005, highlighted that hysterectomy in younger women is associated with complications, hospital stays, procedure-related interference with normal life and is costly. In addition he outlined the need to reduce the number of hysterectomies. This, along with the change in cultural attitudes amongst patients, who are becoming increasingly reluctant to undergo these conventional invasive procedures, has increased the need for new treatment options. Ideally new treatment options for uterine fibroids would be minimally invasive, have long-term data demonstrating efficacy and safety, have minimal or no incidence of fibroid recurrence, be easy to perform, preserve fertility, and be cost effective. New treatment approaches are under investigation, with the goals of being effective, safe, and less invasive. MRgFUS is a non-invasive thermo-ablative hybrid technique which uses both MR and ultrasound to destroy tumours. It is an outpatient procedure, which avoids the need for an anaesthetic, has a short recovery period, and is uterine sparing. The main objective of this work was to set out the rationale for using Magnetic Resonance guided Focused Ultrasound Surgery (MRgFUS) for the treatment of uterine fibroids. In order to achieve this aim, four main bodies of work are necessary; 1) Identifying patient selection criteria and investigating mitigating techniques to increase the pool of women for whom this treatment can be offered. 2) Investigating a method designed to overcome the problem of safely treating women with abdominal scars for whom this treatment can cause potential morbidity. 3) Investigating the potentiality of using MRgFUS to prolong the tumour shrinkage effect of GnRH analogue injections. 4) Investigating the safety of MRgFUS in treating symptomatic women who wish to preserve fertility. Results: the first aim of this project was to identify patient selection criteria and to investigate methods to widen the selection criteria. In our retrospective review it was found that 74% of women presenting were deemed technically suitable to proceed with treatment and several mitigating techniques that solved current technical difficulties were identified and allowed for less restrictive MRgFUS selection criteria for treatment of symptomatic uterine fibroids. These less restrictive criteria are expected to expand the pool of patients for whom MRgFUS is a viable treatment option for uterine fibroid symptoms. The second aim was to identify a method of overcoming the problem of treating women with previous abdominal scars safely. We identified a unique method of highlighting the scar by painting it with a paramagnetic iron oxide material which clearly outlined the scar on MR scanning allowing complete avoidance of the scar using MR guidance. In this small pilot study, all women were treated safely with no skin burns. The third aim of this project looked at the potentiality of prolonging the shrinkage effect of GnRH analogues by following a course of 3 injections with MRgFUS treatment. In this prospective study of fifty women, there was a 50% reduction in the mean symptoms severity score at 6 months which was maintained for 24 months post treatment. There was an average reduction in target fibroid volume which was maintained for 24 months. The final aim of the project was to investigate the safety of using MRgFUS as a treatment option for those women who wished to preserve their fertility. In this multicentre international study, One hundred and sixteen women were recruited from five centres. There were sixty four reported pregnancies in Sixty one women, with 30 completed deliveries. There were no reported cases of uterine rupture, premature labour, abnormal placentation or placental abruption. Conclusion: There is a growing body of data from clinical trials and more than four years of clinical experience to validate the safety and efficacy of MRgFUS for the treatment of uterine fibroids. MRgFUS is a totally non-invasive outpatient procedure that is not associated with the typical surgical risks of bleeding, infection and has minimal recovery time. Additionally, the procedure allows women to address their symptoms whilst preserving the uterus. Consequently, MRgFUS is an alternative treatment option for suitable patients who have refused other interventions due to concerns about lost productivity, risks of surgical complications or future fertility.