MR-Guided Focused Ultrasound Treatment

Abstract

Magnetic resonance-guided focused ultrasound (MRgFUS) is an innovative noninvasive technique for pain management in skeletal metastases. This technology enables the performance of three-dimensional treatment planning with MR imaging and continuous real-time temperature monitoring of target zone with MR thermometric map, ensuring an accurate identification of the lesion and its margins and preventing surrounding healthy tissues from unwanted procedure-related damages. Acoustic energy application on the intact bone surface determines a rapid heating that induces critical thermal damage to the adjacent periosteum, with necrosis of local nerve endings and effective pain management. This procedure has also a potential role in effective local tumor control, allowing the complete ablation of target lesion, or the reduction of its size, and remineralization of trabecular bone. The whole MRgFUS protocol for ablation of bone metastases includes a pre-procedural imaging study, the choice for a strategy of simple palliation of pain or of local tumor control, the choice of the most appropriate anesthetic approach, the technical planning stage, the focal ablation treatment, the post-intervention management, and the clinical and imaging evaluation of treatment outcomes at different subsequent follow-ups.