Safety and efficacy of sonographically guided high-intensity focused ultrasound for symptomatic uterine fibroids: Preliminary study of a modified protocol

Objectives-We aimed to assess the safety and efficacy of sonographically guided highintensity focused ultrasound for treating patients with symptomatic uterine fibroids using a modified protocol.

Methods-This work was part of an ongoing prospective phase 1 study. Twenty patients with 22 symptomatic fibroids were treated with sonographically guided high-intensity focused ultrasound under no anesthesia. The modified protocol consisted of repeated and shortened (<25 minutes) treatment sessions of high-input acoustic intensity (1000-1500 W/cm²) and intensified sonication pulses (1500-2000) at each spot. The primary end points were periprocedural complications. The secondary end points were symptomatic improvement and radiologic evidence of treatment responses, including the degree of fibroid infarction and volume shrinkage 3 months after treatment. Symptomatic improvement was assessed by a pain score, a pictorial chart menstrual score, the Urogenital Distress Inventory short form, and the Incontinence Impact Questionnaire short form. The degree of fibroid infarction was assessed by the nonperfused ratio on contrast-enhanced magnetic resonance imaging, defined as the ratio of the nonperfused fibroid volume to the total fibroid volume.

Results-Nineteen patients tolerated the treatment well, with no major adverse events. One patient who received treatment for a fibroid located within 6 cm from the skin had third-degree skin burns at 2 sites of 1 cm in diameter. Fibroid-related abdominal pain, pictorial chart, Urogenital Distress Inventory, and Incontinence Impact Questionnaire scores were significantly improved (P < .05). The median nonperfused ratio at 3 months was 20% (95% confidence interval, 5%-32.5%). Median volume shrinkage at 3 months was 17.2% (95% confidence interval, 4.3%-26.6%).

Conclusions-Sonographically guided high-intensity focused ultrasound using a modified protocol may be safe and effective for symptomatic uterine fibroids in selected patients to avoid skin burns.