MR-guided high-intensity focused ultrasound (MR-HIFU) is a safe therapy for treating uterine fibroids, especially when it is used with a treatment protocol that aims for complete ablation, according to a study published online on October 15 in the European Journal of Radiology.
In addition, the researchers found that MR-HIFU's reintervention percentage is comparable to uterine artery embolization at 24-month follow-up -- good news, since previous research has suggested that the technique's reintervention rate is high, wrote a team led by Dr. Inez Verpalen of Isala Hospital in Zwolle, the Netherlands.
"To date, several reviews were published on the effectiveness of MR-HIFU treatment for uterine fibroids," the group wrote. "Overall, they showed that MR-HIFU is effective in alleviating symptoms, but a relatively high reintervention percentage is reported. However, these reviews included studies using restrictive treatment protocols that are no longer in clinical use, which affected the results."
Between 70% and 80% of women of reproductive age experience uterine fibroids. Although most women are asymptomatic, about a quarter experience pelvic pain, menstrual cramping, heavy periods, urinary frequency, painful intercourse, and negative effects on their fertility. Of these women, the majority require intervention to remove the fibroids.
For women who wish to preserve their fertility, myomectomy has long been the treatment of choice. However, this procedure has complications and requires not only a hospital stay but weeks of recovery. MR-HIFU is noninvasive, has fewer complications, does not require general anesthesia, and has shorter recovery times. MR-HIFU has been cleared by the U.S. Food and Drug Administration for fibroid treatment since 2004.
Prior research has suggested that the technique has a relatively high reintervention percentage, but these reviews were based on outdated treatment protocols, Verpalen and colleagues wrote. So the group sought to reevaluate the effectiveness of MR-HIFU therapy for uterine fibroids, eliminating studies that used restrictive treatment protocols, such as not seeking complete ablation.
The group searched the National Guideline Clearinghouse, Cochrane Library, Trip, Medline, Embase, and World Health Organization International Clinical Trials Registry Platform databases from their inception through June 2018 using keywords "MR-HIFU," "MR-guided focused ultrasound," and "leiomyoma." The authors only included studies about MR-HIFU treatment of uterine fibroids that had at least three months of clinical follow-up.
The primary outcome of the study was improvement of fibroid-related symptoms post MR-HIFU: The team tracked screening and treatment failures, treatment time, strategies to reduce bowel interference during the procedure -- which can block visualization of the fibroid -- and percentage of nonperfused volume. Secondary outcomes were quality of life, fibroid shrinkage, safety, and the need for additional interventions.
The team found that excluding studies that did not aim for complete fibroid ablation improved outcomes.
| Effectiveness of MR-HIFU for fibroid treatment | |
| Performance metric | Percentage |
| Mean nonperfused volume percentage immediately post-treatment | 68.1% |
| Mean symptom reduction at 12 months postprocedure | 59.9% |
| Mean fibroid shrinkage at 12 months postprocedure | 37.7% |
| Percentage of adverse events | 8.7% |
| Need for additional interventions from 3 to 33 months | 0% to 21% |
The study demonstrates that MR-HIFU is an effective way to treat uterine fibroids, the group concluded.
"Symptom improvement in this review was greater compared with other MR-HIFU reviews and the retreatment rates were lower," the team concluded. "The reintervention percentage is comparable to uterine artery embolization at 24 months follow-up."
