Relief from fibroids can be achieved through treatment with magnetic resonance (MR)-guided focused ultrasound -- a completely non-invasive therapy, researchers reported here at the 91^st scientific assembly and annual meeting of the Radiological Society of North America (RSNA).

As many as 85% of women who underwent MR-guided focused ultrasound said they were pain free a year after the procedure, they said.

"This treatment immediately stops blood flow in the fibroid tissue, which results in a significant, sustained decrease in symptoms for up to 12 months," said Fiona Fennessy, MD, Instructor of Radiology, Harvard Medical School, and Staff Radiologist, Brigham and Women's Hospital, Boston, Massachusetts, United States.

In fact, results obtained from a cohort of patients who completed a quality of life questionnaire before and after the treatment show that pain and other factors dropped by 50% within 3 months of the procedure and that decrease was maintained for about 1 year, Dr. Fennessy said in a press briefing.

Uterine fibroids can sometimes grow so large that they can put pressure on the woman's bladder or her back, causing pain and discomfort and intervening in activities of daily living.

The procedure uses high doses of focused ultrasound waves to destroy uterine fibroids, without affecting any of the other tissues around the fibroid. The woman receives oral sedation and lies on her stomach for about 2 hours while the doctor focuses the ultrasound energy on various parts of the fibroid, killing about 7 cm of the fibroid.

Dr. Fennessy said that women experience no significant adverse effects from the procedure.

She described her study, which enrolled 147 women with fibroids that were causing symptoms. In an earlier phase of the study, 96 women with fibroids that were less than 6 cm in diameter were treated for as long as 2 hours; a second group of 51 women were treated in an expanded protocol that allowed them to treat larger fibroids for up to 3 hours.

The researchers used the Uterine Fibroid Quality of Life Questionnaire (UFQoLQ) to measure fibroid symptoms using a scale of 1 to 99, with a score of 22 being a normal condition.

Both treatment protocols demonstrated efficacy at all time points -- 3 months, 9 months and 12 months -- but the best results were achieved with the expanded protocol, according to patient responses to the UTQoLQ.

The women had an average score of 60 at the start of the study and 30 at study end, a difference that reached significance at the P < .0001, Fennessy said. Under the original protocol 75.8% of women had significantly improved symptoms at 12 months, while 85.7% of women treated with the expanded protocol reported significant improvement at that time point.

Michael Brant-Zawadzki, MD, Medical Director of Radiology, Hoag Memorial Hospital Presbyterian, Newport Beach, California, United States, said the MR-guided focused ultrasound system is a major advance in uterine fibroid management.

"A nice aspect of this [treatment] is that the magnetic resonance monitors the heat in the fibroid so it is relatively easy to determine when the ablation is complete. It's like the thermometer that pops up in the turkey," he said.

Dr. Brant-Zawadzki, who serves as chairman of the RSNA communications committee, said he regularly performs uterine fibroid embolizations, the minimally invasive procedure that shrinks fibroids by cutting off their blood supply with the use of occlusive agents. But he said that his center has recently received funding to start a focused ultrasound study. He predicted that many interventional radiologists will be offering both treatments.

Dr. Fennessy performed the treatments with the ExAblate 2000 system made by InSightec, Inc., which is currently the only Food and Drug Administration-approved device for ultrasound ablation of uterine fibroids. InSightec, Inc., sponsored the study.