Clinical predictors of successful magnetic resonance-guided focused ultrasound (MRgFUS) for uterine leiomyoma

BACKGROUND: Magnetic resonance-guided focused ultrasound (MRgFUS) is a relatively new minimally invasive treatment, approved by the US Food and Drug Administration in 2004 for treatments of symptomatic uterine leiomyomas (fibroids). The purpose of this work is to present retrospective cohort analysis of women that underwent commercial MRgFUS treatment between 2005 and 2009 at a single center, to identify baseline patient characteristics that predict successful MRgFUS fibroid treatment. Identifying these clinical predictors of MRgFUS would be helpful to clinicians choosing the optimal patient for this treatment modality. METHODS: One hundred thirty women with symptomatic uterine leiomyomas who underwent MRgFUS were followed up with a mean length of follow up of 17.4 ± 10.3 months. The main outcome measure of the follow-up was to identify patients who required additional fibroid treatment due to continued fibroid symptoms. Additionally, patient medical history and radiological findings obtained prior to MRgFUS were reviewed, and statistical analysis was performed to identify factors associated with reduced risk of having additional fibroid treatment. RESULTS: Twenty-nine patients (22.3%) underwent additional fibroid treatment due to continued or recurrent fibroid symptoms during the follow up. Cumulative incidence of additional fibroid treatment was 9.7%, 29.3%, and 44.7% at 1, 2, and 3 years following MRgFUS, respectively. In multivariable Cox proportional hazard regression analyses, older age (hazard ratio (HR) 0.54 per 5-year increase in age, 95% confidence interval 0.39 to 0.76, p < 0.001), greater number of fibroids (HR 0.19 for more than three vs. one fibroid, 95% CI 0.05 to 0.67, p = 0.033), and greater fibroid volume (HR 0.70 per doubling in volume, 95% CI 0.51 to 0.96, p = 0.025) were significantly associated with less risk of having additional fibroid treatment. CONCLUSIONS: Older age at treatment and having multiple fibroids with larger volume are associated with a lower risk of additional intervention following MRgFUS treatment for uterine fibroids.