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

Phase 1/Phase 2
18 Years
59 Years
Not Enrolling
Uterine Fibroids, Uterine Leiomyomata

Thank you

Trial Information

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.

Primary Outcome parameters:

1. Verifying with MR imaging that the location of the HIFU lesion matches the expected
location (binary)

2. Verifying with MR imaging that no unintended lesions are formed as a result of the
treatment (binary)

3. Examining the uterine capsule and surrounding areas for unintended damage during
hysterectomy (binary)

4. Evaluating any complications or adverse events that result from the MR-guided HIFU
treatment (categorical)

5. Comparing the actual MR-measured ablated volumes to MR thermal dose predicted volumes

6. Comparing the ablated volumes from histology to MR thermal dose predicated volume

7. Ensuring on histopathologic examination of the uterus that the zones treated by
MR-guided HIFU treatment are indeed necrosed (binary)

Secondary Outcome Parameters:

1. Pain and discomfort scores immediately before, during and after HIFU treatment:

2. Length of Hospital Stay (LOS)

3. Return to Activity

Inclusion Criteria


1. Recommended for Total Abdominal Hysterectomy

2. Age between 18 and 59

3. Weight less than 140kg (or 310lbs)

4. Pre or peri menopausal with FSH less than 40 mIU/ml

5. Uterine size less than 24 weeks based on MRI and physical exam assessment

6. Symptom severity score greater than or equal to 50 by Spies Uterine Fibroid

7. Cervical cytology no more severe than low grade SIL

8. History of uterine leiomyoma causing symptoms of bleeding, pressure, or pain, as
defined by the ACOG practice bulletin (ACOG Practice Bulletin 1994):

9. Dominant intramural fibroid greater than or equal to 3 cm and less than or equal
to 16 cm on imaging.


1. Other pelvic disease (mass indicated by history or MR imaging such as endometriosis,
ovarian tumor, acute or chronic pelvic inflammatory disease)

2. Desire for future pregnancy

3. Significant systemic disease even if controlled

4. Pregnant or Positive pregnancy test

5. Hematocrit less than 25%

6. Extensive scarring along anterior lower abdominal wall (greater than 50% of area) or
scar tissue or surgical clips in the direct path of the HIFU beam

7. MRI or MRI contrast agent contraindicated

8. Unable to quantify or measure fibroids on MR exam including nonenhancing fibroids

9. Fibroid or uterine calcifications

10. Dominant fibroid is pedunculated or greater than 5 cm submucosal

11. Communication barrier

Type of Study:


Study Design:

Endpoint Classification: Safety/Efficacy Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Treatment

Outcome Measure:

Treatment-related Adverse Events (AE) Per Subject Resulting From HIFU Treatment of the Uterine Fibroids

Outcome Description:

The number of treatment-related Adverse Events (AE) reported during the study, divided by the total number of treated subjects. This corresponds to the mean number of treatment-related Adverse Events per subject. Relatedness of an AE to the treatment was judged case-by-case by the investigator.

Outcome Time Frame:

end of follow-up (date of hysterectomy, at latest day 30 after treatment)

Safety Issue:



United States: Food and Drug Administration

Study ID:




Start Date:

January 2009

Completion Date:

December 2010

Related Keywords:

  • Uterine Fibroids
  • Uterine Leiomyomata
  • High Intensity Focused Ultrasound Ablation
  • Uterine Fibroids
  • Leiomyomata
  • Non-Invasive Treatment of Uterine Fibroids
  • MRI-Guided
  • Fibroids
  • Uterine Leiomyomata
  • Leiomyoma
  • Myofibroma



National Institutes of Health Clinical Center, 9000 Rockville PikeBethesda, Maryland  20892
St. Luke's Episcopal HospitalHouston, Texas  77030