FDA okays first MR-guided focused ultrasound ablation system

The FDA gave final approval last Friday for marketing of the first MR-guided focused ultrasound ablation system for treatment of uterine fibroids. Application caveats remain, however.

InSightec's ExAblate 2000 got the Feds' nod following a recommendation in June from an independent panel of experts. The approval process included review of several clinical studies on safety and effectiveness and the manufacturer's reassessment of training and labeling issues. Expedited approval came as a result of the device's significant advantages over existing treatments for uterine fibroids, the FDA said.

The ExAblate system integrates focused ultrasound thermal ablation with MR imaging guidance. MR guidance helps visualize both the fibroid and the surrounding structures, monitor the appropriate temperature required to cause tissue coagulation, and control ablation to avoid the destruction of normal tissue.

Treatment consists of repeated targeting and heating of fibroid tissue while the patient lies inside the MR scanner. Patients treated in clinical trials have reported minimal pain after ablation, and most do not need pain medication.

The outpatient procedure does not require any type of surgical incisions. It takes from one to three hours to complete, and patients resume normal activities usually within two days, which minimizes negative implications, said Rob Newman, vice president of Dallas-based InSightec North America.

There are several application limitations. The device is not intended for women who are seeking pregnancy and will be limited for pre- or postmenopausal women who have completed their families. It cannot treat fibroids close to sensitive organs or outside the image area, and no more than two treatments should be performed in a two-week period, Newman said.

The procedure could alter the composition and strength of the uterine tissue. The effects of the treatment on the ability to become pregnant and carry a fetus to term or on the development of the fetus have not been determined. Following FDA instructions, InSightec should conduct a three-year postmarket study to better assess ExAblate's long-term safety and effectiveness. The study will also include additional numbers of African American women due to their greater incidence of uterine fibroids, Newman said.

The system is compatible only with GE Healthcare SIGNA 1.5T MR scanners and is in operation at major research centers, including the Brigham and Women's, Johns Hopkins, and the Mayo Clinic, Rochester. The device had previously received the CE mark and is already commercially available in Israel, Europe, and Asia. Use of the device may have far-reaching implications, according to Newman.

"We believe that this will be a significant contribution to healthcare, first to the treatment of fibroids and then in other treatment areas. We look forward to continuing this development of image-guided therapy to explore the possibilities," he said.

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