Decreasing margins to the uterine serosa as a method for increasing the volume of fibroids ablated with magnetic resonance-guided focused ultrasound surgery

Abstract Objective To demonstrate the safety of magnetic resonance-guided focused ultrasound surgery (MRgFUS) treatments regardless of the distance between the treatment region and the uterine serosa. Study design 83 pre-menopausal women with symptomatic uterine fibroids were treated with MRgFUS in 88 treatments. Treatment data was analyzed, measuring the distance between the treatment spots (sonications) and the serosa. Patients were followed up for 1 year and adverse events were collected. Results 79% and 37% of the sonications were less than 15 mm and 10 mm from the serosa, respectively. Treatment was always confined to the fibroid capsule. There were no unexpected or serious adverse events. Conclusion Reducing the margin between the fibroid treatment area and the uterine serosa, when possible, enables MRgFUS treatment of greater fibroid volume, while maintaining a high safety profile. Special attention should be paid when the uterus lies adjacent to other sensitive organs to avoid unintentional heating of these organs, using the planning and real-time MR images.