Safety and treatment volumes achieved following new developments of the magnetic resonance-guided focused ultrasound system in the treatment of uterine fibroids: a cohort study

Abstract

BackgroundThis research investigates whether modifications to the magnetic resonance-guided focused ultrasound ablation of uterine fibroid (MRgFUS) system used resulted in improved treatment volumes of uterine fibroids, while maintaining safety.MethodsThis study is a prospective cohort analysis of 34 women undergoing the ExAblate 2100 MRgFUS treatment for their uterine fibroids.ResultsThe percentage of non-perfused volume (NPV) achieved with the ExAblate 2100 system was 54.92% compared with 50.49 % with the ExAblate 2000 system over the preceding year (p = 0.543). The ExAblate 2100 system resulted in a greater NPV in hyper-intense fibroids compared with the ExAblate 200 system (43.20% versus 36.33%, p = 0.005). There have been no recorded hospital admissions, no skins burns, and no reported major adverse events since the introduction of this new system.ConclusionOverall, the new system has thus far shown an encouraging safety record and an improvement in non-perfused volumes achieved, especially in hyper-intense fibroids.

European Society of Urogenital Radiology (ESUR) Guidelines: MR Imaging of Leiomyomas

“…Post treatment predictor of success is the non-perfused volume of the leiomyoma. Treatment typically achieves around 50–55% non-perfused volume, based on post contrast imaging after the completion of treatment [ 52 ].…”

Safety and five-year re-intervention following magnetic resonance-guided focused ultrasound (MRgFUS) for uterine fibroids

“…The introduction of the ExAblate 2100 system has increased the NPVs achieved in fibroids, in particular in those fibroids of higher signal intensity [20]. A study by Trumm et al found mean NPV ratios of 88 AE 15% (range 38-100%) using the new ExAblate 2100 system [21].…”

AAPM Task Group 241: A medical physicist’s guide to MRI‐guided focused ultrasound body systems

“…Independent control of element phase and amplitude is important for active tissue aberration correction. First, phase control allows the electronic steering of the focus, which can enlarge the treated volume and increase treatment efficiency 30,31 . Second, the ability to deactivate specific transducer elements allows the user to avoid sonicating through normal tissues or organs at risk, such as the ribs, nerves or bowel 32 …”

“…First, phase control allows the electronic steering of the focus, which can enlarge the treated volume and increase treatment efficiency. 30,31 Second, the ability to deactivate specific transducer elements allows the user to avoid sonicating through normal tissues or organs at risk, such as the ribs, nerves or bowel. 32 The drive electronics are sited with the MR electronics and fed through filtered penetration panels into the treatment room.…”