Pilot Study of MRI-Guided High Intensity Focused Ultrasound Ablation of Uterine Fibroids

Uterine fibroids (leiomyomas) are a common cause of heavy uterine bleeding and pain in reproductive aged women and are the most common cause of hysterectomy in the United States. Women are seeking new ways to treat symptomatic uterine fibroids that allow them to avoid surgery. This study is the first step in this quest. We will study the novel use of magnetic resonance imaging (MRI) in enhancing the safety of the FDA approved technique to treat fibroids called High Intensity Focused Ultrasound (HIFU). The term 'high intensity focused ultrasound' means using ultrasound to heat and to thermally destroy tissue, in this case, uterine fibroids. The MRI system will allow us to watch the ultrasound path during treatment and monitor the temperature increase in the fibroid tissue that comes during the procedure.

In this pilot study, women with symptomatic fibroids will undergo MRI guided HIFU and then have a hysterectomy. This will allow us to confirm studies done in animals which show that it is possible to destroy specific tissue without harming normal tissue surrounding the targeted area.

The purpose of this clinical study is to confirm the safety and treatment capabilities of the Philips MR guided HIFU system for ablation of uterine fibroids. This is a single arm pilot study of 10 women who will undergo hysterectomy after the HIFU procedure. This study design of hysterectomy after treatment has been requested by the FDA as part of IDE approval for this new device and mirrors what has been required for similar devices. Safety will be assessed by evaluating treatment accuracy, complications, and adverse events. Treatment capabilities will be assessed by evaluating the fibroid volume ablated and other factors related to the procedure feasibility and acceptance including procedure duration, time to return to normal activity, and pain scores at the time of the procedure.

Study population

The Philips MR-HIFU System is intended for ablation of uterine fibroid tissue in pre- or perimenopausal women with symptomatic uterine fibroids who desire a uterine-sparing procedure. Patients must have completed child bearing prior to enrolling in this study. Patients will be recruited by referral to gynecology and interventional radiology at the NIH Clinical Center. Candidates for enrollment will already have symptomatic uterine leiomyomas and be willing to undergo hysterectomy for treatment. It is estimated that of apparently eligible subjects, at least 30 women will have to be screened in person in order to identify 10 who will be eligible for this study. Other studies of fibroid treatments are currently ongoing at the NIH. Women who have been interested in, but have not been selected for enrollment in those studies and who appear to be eligible to this study will be contacted for potential enrollment.

Study design:

This study is a multi-center, single arm trial evaluating the safety and treatment capabilities of the Philips MR-guided HIFU system in the treatment of symptomatic uterine fibroid patients who are otherwise healthy women. All patients enrolled in the study will undergo hysterectomy within a window of 30 days following HIFU treatment. Patients who have symptomatic uterine fibroids, meet clinical indications for hysterectomy, are eligible according to the inclusion and exclusion criteria and provide informed consent will be enrolled in this study. This study design of treatment followed by hysterectomy has been requested by the FDA as part of IDE approval for this new device and mirrors what has been required for similar devices. It is anticipated that women will participate in the study for a 3 month period to include the screening, HIFU treatment, hysterectomy and post hysterectomy follow-up.

The methodology used for this HIFU device capitalizes on the thermal properties of volumetric ablation rather than point ablation used by other focused ultrasound systems. Thus it is anticipated that this device will have a shorter treatment time compared to other HIFU machines. This HIFU system, via real-time MR thermometry monitoring, has automated thermal feedback during the procedure which may enhance safety. This pilot study will not only assess the safety of this device but will enable us to delineate the treatment capabilities of this system for future use in patients who want uterine sparing non-surgical treatment for symptomatic fibroids.