Potential benefit of GnRH-agonist treatment before uterine artery embolization for large fibroids: MRI prediction of fibroid volume reduction.

Abstract

Signal intensity (SI) of predominant fibroid (F1) on T2-weighted (T2W) images is useful for predicting the volume reduction response after gonadotropin-releasing hormone (GnRH)-agonist treatment. Few studies have been published regarding when and how to use GnRH agonist before UAE. To investigate magnetic resonance imaging (MRI) prediction of volume reduction rate (VRR) of large fibroids after GnRH-agonist treatment before uterine artery embolization (UAE) as well as the efficacy of UAE based on MRI. Data from 30 patients with a large fibroid and MRI results both before and after GnRH-agonist treatment were retrospectively analyzed. Indications for GnRH-agonist treatment are fibroids with a maximum diameter ≥10 cm or pedunculated submucosal fibroids ≥8 cm. GnRH agonist (3.75 mg leuprolide acetate) was administered subcutaneously once per month 2-6 times. SI of F1 on T2W imaging was measured: the SI was referenced to the SI of the rectus abdominis muscle (F/R). Mean maximum fibroid diameter was 11.1 ± 1.9 cm (range = 8.0-15.5 cm). Mean number of GnRH-agonist injections before UAE was 2.8 (range = 2-6). For predicting VRR ≥50% and <30%, the optimal cut-off values of F/R were 2.58 (sensitivity 80%, specificity 80%) and 1.69 (sensitivity 100%, specificity 70%), respectively. Of the 30 patients, fibroid infarction was complete in 29 (96.7%). SI of F1 on T2W imaging is useful for predicting the volume reduction response after GnRH-agonist treatment. After GnRH-agonist treatment for large fibroids, UAE is effective to achieve complete infarction of fibroids.