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

Background: 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. Purpose: 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. Material and Methods: 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). Results: 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%). Conclusion: 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.