PROMISe trial: a pilot, randomized, placebo-controlled trial of magnetic resonance guided focused ultrasound for uterine fibroids.

OBJECTIVE: To evaluate the feasibility of a full-scale placebo-controlled trial of magnetic resonance-guided focused ultrasound for fibroids (MRgFUS) and obtain estimates of safety and efficacy.

DESIGN: Pilot, randomized, placebo-controlled trial.

SETTING: University medical center.

PATIENT(S): Premenopausal women with symptomatic uterine fibroids.

INTERVENTION(S): Participants randomized in a 2:1 ratio to receive MRgFUS or placebo procedure.

MAIN OUTCOME MEASURE(S): change in fibroid symptoms from baseline to 4 and 12 weeks after treatment assessed by the Uterine Fibroid Symptom Quality of Life Questionnaire (UFS-QOL); secondary outcome: incidence of surgery or procedures for recurrent symptoms at 12 and 24 months.

RESULT(S): Twenty women with a mean age of 44 years (±standard deviation 5.4 years) were enrolled, and 13 were randomly assigned to MRgFUS and 7 to placebo. Four weeks after treatment, all participants reported improvement in the UFS-QOL: a mean of 10 points in the MRgFUS group and 9 points in the placebo group (for difference in change between groups). By 12 weeks, the MRgFUS group had improved more than the placebo group (mean 31 points and 13 points, respectively). The mean fibroid volume decreased 18% in the MRgFUS group with no decrease in the placebo group at 12 weeks. Two years after MRgFUS, 4 of 12 women who had a follow-up evaluation (30%) had undergone another fibroid surgery or procedure.

CONCLUSION(S): Women with fibroids were willing to enroll in a randomized, placebo-controlled trial of MRgFUS. A placebo effect may explain some of the improvement in fibroid-related symptoms observed in the first 12 weeks after MRgFUS.

CLINICAL TRIAL REGISTRATION NUMBER: NCT01377519.