Data review supports efficacy of MR-guided focused ultrasound

May 18, 2007

Treatment guidelines from the FDA limit the ultrasonic ablation of uterine fibroids to 50% of the lesion mass, as seen and targeted with MRI, a limitation that has raised doubts in the medical community about whether the treatment can be effective. But Dr. Phyllis Gee, medical director of the North Texas Uterine Fibroid Institute in Plano, says physicians need not be concerned about the efficacy or long-lasting effect of this treatment.

Treatment guidelines from the FDA limit the ultrasonic ablation of uterine fibroids to 50% of the lesion mass, as seen and targeted with MRI, a limitation that has raised doubts in the medical community about whether the treatment can be effective. But Dr. Phyllis Gee, medical director of the North Texas Uterine Fibroid Institute in Plano, says physicians need not be concerned about the efficacy or long-lasting effect of this treatment.

Gee is a principal investigator at one of eight luminary sites that have evaluated MR-guided focused ultrasound using technology developed by GE Healthcare and the Israeli firm Insightec. After reviewing the study data, she concluded that the treatment is indeed effective at relieving symptoms over the long and short term, and reported this in a poster presentation at the American College of Obstetrics and Gynecology meeting.

"Ideally you would like the fibroid to be entirely black, indicating nonperfused volume (total ablation) on the post-treatment MRI," she told DI SCAN. "But we found that it doesn't have to be 100%. If you just treat at least 50%, you get a good result."

Demonstrating efficacy within the FDA-established guidelines is key to the adoption of this technology, using ultrasound transducers mated to GE Signa MR scanners. The hybrid device was approved by the FDA in October 2004.

The two companies are promoting their approach as an alternative to invasive treatments, which include hysterectomy, myomectomy (the excision of fibroids through an abdominal incision), or uterine artery embolization.

"This tool is really best suited to women who have one to six fibroids that are moderate to large as opposed to very large," Gee said.

Millions of women in the U.S. compose this select group of patients, many of whom "suffer in silence because they don't want the treatment options being presented to them," she said. "This offers these women an option they haven't previously had."

Original research conducted by GE Healthcare indicates that clinically significant uterine fibroids are common among women ages 25 to 54, according to David Lee, Ph.D., senior director for health economics and outcomes research. Fibroids, along with several associated conditions including endometriosis, menstrual disorders, and pain with anemia, impose substantial costs personally and professionally.

"Fibroids become problematic when they start interfering with daily activities," he said.

Limitations placed on the use of the MR-guided technology, specifically limiting ablation to a total of 50% of the fibroid mass, have made physicians skeptical about whether MR-guided focused ultrasound can be effective, Gee said. Her research examining the efficacy and duration of effect indicates that those worries are misplaced.

"These findings should give physicians the confidence to go forward," she said. "MR-guided focused ultrasound is a viable option for the right patient."