Suzanne Denise LeBlang MD, Presenter: Nothing to Disclose

To assess the degree of leiomyoma ablation and shrinkage after magnetic resonance-guided focused ultrasound (MRgFUS) treatment in a private practice outpatient setting using current less restrictive protocols.

A total of 145 leiomyomas in 80 symptomatic female patients with an average age of 46 years (34-55) were treated with MRgFUS. Pretreatment T2 weighted planning images were used to measure the leiomyomas volume, and post-treatment T1 weighted contrast-enhanced images were used to measure non-perfused volume (NPV). Similar images obtained 6 months post-treatment were used to determine leiomyoma shrinkage. Student’s paired t test, ANOVA single factor test, and linear regression were used to measure relationships between fibroid volume, NPV at treatment, and 6 month shrinkage.

The average treated fibroid volume was 177 ± 201 cc (n=145), with average NPV of 55% ± 25% immediately post-treatment. At 6 months post-treatment, average volume of treated fibroids was reduced to 112± 141 cc (n=80) (P<0.0001) with average shrinkage of 31% ± 28%. A linear regression model showed a highly significant correlation between post-treatment NPV ratio and shrinkage at 6 months (P<0.0001).

MRgFUS of leiomyomas in an outpatient practice can yield NPV and shrinkage that exceeds previous results from clinical trials likely due to more relaxed treatment guidelines and improved operator experience. Results suggest that practitioners should strive for a treatment NPV of at least 50%, with larger NPVs yielding greater shrinkage thus resulting in improved clinical outcomes.

Higher post-treatment non-perfused volumes correlate with increased leiomyoma shrinkage which has already been proven to decrease symptomotology.  

LeBlang, S, Leiomyoma Shrinkage after ExAblate MR-guided Focused Ultrasound: Report of 80 Outpatient Commercial Patients.  Radiological Society of North America 2008 Scientific Assembly and Annual Meeting, February 18 - February 20, 2008 ,Chicago IL. http://archive.rsna.org/2008/6021396.html