A sound approach to fibroids

A new interventional radiology tool based on using magnetic resonance imaging to guide focused high-energy ultrasound could be used to thermally ablate uterine fibroid tissue and relieve symptoms of this condition without major invasive surgery.

A uterine fibroid, also known as uterine leiomyoma, is a benign (non-cancerous) tumour that originates from the smooth muscle layer, the myometrium, of the uterus, and the associated connective tissues. Fibroids are most common in the middle and later reproductive years and are generally asymptomatic but can grow substantially leading to heavy and painful menstruation, painful sexual intercourse, and an increase in urinary frequency and urgency. Sometimes fibroids are severe enough to cause anaemia requiring blood transfusion, disabling pelvic pain and pressure. They can cause miscarriage, interfere with fertility in general and lead to an abnormally large uterus that resembles pregnancy.

Twenty to 40 percent of women age 35 and older have uterine fibroids of a significant size. African-American women are at a higher risk for fibroids: as many as 50 percent have fibroids of a significant size. They are a major indication for hysterectomy in the USA.

Now, Gina Hesley of the Mayo Clinic in Rochester, Minnesota and her colleagues have turned to magnetic resonance guided focused ultrasound, MRgFUS, as an alternative to the major surgerical procedure that is often needed in majaor cases of multiple fibroids, leiomyomatosis, in which the number of fibroids grows too high to count accurately.

The researchers studied more than 100 patients and found that they could provide women with lasting relief from uterine fibroid-related symptoms using MRgFUS, the team reported at the Society of Interventional Radiology's 35th Annual Scientific Meeting in Tampa, Florida, on 13th March this year.

"Our 119-patient study shows that MRgFUS is highly effective and can provide lasting relief from uterine fibroid-related symptoms," said Hesley. Follow up with the patients at 12 months showed that 97 percent of the women reported improvement of their symptoms, with 90 percent of women rating their improvement as either considerable or excellent.

MRgFUS is a newer technique than another interventional radiology fibroid treatment - uterine fibroid embolization or UFE. This technique is a widely available treatment used to stymie blood flow to the fibroid growths.

MRgFUS is performed as an outpatient procedure in which the high-intensity ultrasound causes localised heating that destroys, or ablates, the fibroid tissue. "Our results with effectiveness of MRgFUS technology are promising and comparable with that of UFE, but its longer-term effectiveness needs continued study," added Hesley. "Today, women have interventional radiology options that do not involve the use of a scalpel incision. Women should ask for a consultation with an interventional radiologist who can determine from MR imaging whether they are candidates for either procedure," she added.

MRI gives the physician a clear view of the position, size and shape of the fibroids so that precisely focused ultrasound energy can be delivered. MRI also enables the physician to monitor tissue temperature in real-time to ensure adequate - but safe - heating of the target. Immediate imaging of the treated area following MRgFUS helps the physician determine the success of the treatment.

The US Food and Drug Administration approved MRgFUS for the treatment of uterine fibroids in October 2004 and the current long-term study at the Mayo Clinic has provided additional evidence of its efficacy. The researchers point out that the rate of follow-up treatment after initial MRgFUS was just 8 percent, which is within values reported for myomectomy and uterine fibroid embolization.

The Mayo researchers will continue to study two-year and three-year results of symptom relief. They will also compare their current results with those reported for myomectomy and uterine artery embolization and investigate the efficacy of MRgFUS in treating other uterine conditions, such as adenomyosis, a condition in which tissue that normally lines the uterus also grows within the muscular walls of the uterus, said Hesley.

The views represented in this article are solely those of the author and do not necessarily represent those of John Wiley and Sons, Ltd.