VIENNA — The least invasive treatment for uterine fibroids is not always the most effective, according to a new study.
However, magnetic-resonance-guided high-intensity focused ultrasound might still be the best option for many patients with symptomatic fibroids, said Marlijne Ikink, MD, from the University Medical Center Utrecht in the Netherlands.
"It's a very good treatment option for a specific group of patients — mostly those with single dominant fibroids that are not too big and have a very low signal intensity. I think it's a very helpful treatment for patients who wish to become pregnant in the future," Dr. Ikink told Medscape Medical News.
"Patients and gynecologists want a treatment that is less invasive than uterine artery embolization. I think this is it, but we have to improve the efficiency," she noted.
Dr. Ikink presented the study results here at the European Congress of Radiology 2014.
Of the 119 women with symptomatic fibroids evaluated, 51 were treated with magnetic-resonance-guided high-intensity focused ultrasound and 68 were treated with uterine artery embolization. All women met the eligibility criteria for both procedures, which included fibroids of 12 cm or less, 5 or fewer fibroids, and the absence of interposed intestines or other pelvic diseases.
At 3-month follow-up, median symptom severity scores had improved significantly from baseline in both groups, from 65.3 to 21.9 in the embolization group (P < .001) and from 53.1 to 34.4 in the ultrasound group (P < .001).
Health-related quality-of-life scores also improved significantly in both groups, from 48.5 to 85.4 in the embolization group (P < .001) and from 60.3 to 81.5 in the ultrasound group (P < .001).
However, after adjustment for baseline differences, women in the embolization group were 14.9 times more likely to have a clinically relevant improvement in symptoms at 3 months than those in the ultrasound group, she said.
At 12 months, patients in the ultrasound group were 7 times more likely to have had a reintervention (P = .002).
"In other words, 35% of the ultrasound patients needed additional treatment within 12 months, compared with 5% of the embolization patients," Dr. Ikink reported.
"One explanation for the different failure rates is that embolization treats all fibroids at one time, whereas in patients undergoing ultrasound, only selected fibroids are treated," said Vera Fröling, MD, from Charité Universitätsmedizin Berlin in Germany. Her team published similar results last year (Eur J Radiol. 2013;82:2265-2269).
This study "confirms my feeling about embolization and MR-focused ultrasound," Togas Tulandi, MD, from McGill University in Montreal, told Medscape Medical News. "Embolization blocks the uterine vessels, while focused ultrasound is directed toward individual fibroids. The cost of ultrasound is also higher," he said.
Dr. Fröling pointed out that nonperfused volume is an important variable that can "massively" influence ultrasound outcome.
Dr. Ikink explained that in the first 3 years of ultrasound treatment at her center, the nonperfused volume was only 40%. "We had a lot of restrictions in the protocol and we had to take a lot of margins around the fibroid," she said.
Success rates have since improved. "We know from the literature that you have to reach at least 60% to have adequate ablation. We are there now," she said.
However, even with adequate nonperfused volume and ablation, the treatment is not appropriate for all patients, she said.
"I don't think you can use ultrasound instead of embolization, but you can use the treatment for a specific group," Dr. Ikink said. "Almost all patients with uterine fibroids can be treated with embolization, but that's not the case with ultrasound. About 60% are not eligible because of the size or number of fibroids, the amount of vascularity, or the interposition of the bowel loops," she explained.
In contrast, embolization is more invasive and presents more risks, making ultrasound a popular choice for clinicians and patients.
"With uterine artery embolization, there is risk of postembolization syndrome, vaginal fibroid expulsion, and unintended ovarian embolization leading to premature menopause and infertility," Dr. Ikink said. "Magnetic-resonance-guided high-intensity focused ultrasound is a noninvasive technique, it does not affect ovarian function, and does not involve exposure to radiation."
Dr. Ikink and Dr. Fröling have disclosed no relevant financial relationships.
European Congress of Radiology (ECR) 2014: Abstract B-0260. Presented March 6, 2014.
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Cite this: Newer Uterine Fibroid Treatment Affords Less Efficacy, Risk - Medscape - Mar 07, 2014.