Post Approval Study: MR Guided Focused Ultrasound Surgery in the Treatment of Uterine Fibroids
Uterine leiomyoma (fibroids) are the most common neoplasms of the female pelvis. These
benign tumors are generally oval in shape, and often highly vascular. On T2 weighted MR
imaging exams, or T1 exams with contrast, uterine fibroids are easily identifiable. They
occur in 20-25% of women of reproductive age and can cause a variety of problems generally
described as either bleeding or mass effects from the fibroid. In general, these symptoms
can be classified into two categories:
1. heavy menstrual bleeding, defined as bleeding on heavy days requiring a change of
sanitary wear every 2 hours or less, significant clot passage, flooding, substantial
prolongation of menstrual periods compared with the patient's prior experience, or
2. pelvic pain or pressure, heaviness or discomfort, or similar symptoms in the back,
flank or leg attributable to the bulk of the fibroid, urinary frequency, increase in
nocturia, difficulty voiding or compression of the ureters with hydronephrosis.
Measures of the clinical success of patients who elect treatment of fibroids are generally
subjective, and evaluated by the patient in terms of improvement in the initial symptoms
that caused her to seek treatment (decrease in pain, bladder or bowel symptoms, or reduction
in vaginal bleeding), while experiencing a minimum of co-morbidities from the treatment
The InSightec ExAblate MR guided Focused Ultrasound Surgery (MRgFUS) system is a
non-invasive thermal ablation device fully integrated with an MR imaging system and used for
the ablation of soft tissue. It has been evaluated in an earlier FDA international,
multi-center study and found to be safe and effective for the treatment of uterine fibroids.
ExAblate device received FDA approval in October 2004.
The ExAblate has been used for the treatment of uterine fibroids in 2 previous IDE
- Group A: This was the original Pivotal Study Group (IDE G020001 - Protocol UF002).
These 109 patients were treated at 3 sites in the US and at 4 sites outside the US.
There was a limitation on the allowable treatment volume and only a single treatment
was permitted. Original follow-up was planned for 6 months. The study was later
extended to include follow-up visits at 12, 24, and 36 months (UF009). Because of the
gap between the initial study consent, and the re-consent for the long term follow-up
there was a high dropout rate at the 12 month visit. Thirty-three US patients returned
for the 12 months visit, and will continue to be followed for the 24 and 36 M visits.
- Group B: This was the Continued Access Study (IDE G020001 - Protocol UF005) where
approximately 160 patients were treated at 3 sites in the US during the PMA review
period. Treatment conditions were modified somewhat from the pivotal, including the
addition of a second treatment session where necessary. The initial study was planned
to include a long term follow-up of 12, 24 and 36 months (UF009).
- Group C: This group of 70 patients (UF14) will be treated post-PMA approval following
the commercial treatment guidelines. The follow-up will include for visits at 12, 24
and 36 months. This group includes also another 20 patients who will be treated under
this original IDE to validate the ExAblate system for use in a 3T MR scanner, as well
as validating a new application SW (V4.1).
Allocation: Non-Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Treatment
Treatment/Ablation of Uterine Fibroids
Within 1 month of treatment
Robert Min, M.D.
United States: Food and Drug Administration
UF014 - 4.1/3T
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