Image-Guided Focused Ultrasound for the Treatment of Bone Metastases: Current Status and Future Direction

Bone metastases are a pervasive problem in oncology. For many of these patients, pain due to osseous metastases is the predominant factor negatively influencing quality of life. High-intensity focused ultrasound (FUS) therapy is a novel technology used for the treatment of bone metastases. FUS can be done with either ultrasound or magnetic resonance guidance (USgFUS or MRgFUS respectively). We review the outcomes and toxicity of current studies using USgFUS and MRgFUS for the treatment of bone metastases. A recently completed phase III trial has confirmed statistically and clinically significant benefit in pain control and quality of life for patients with painful bone metastases who were not candidates for radiation therapy. Future areas of research include expansion of sites suitable for MRgFUS treatment, applicability of MRgFUS as a primary treatment for painful bone metastases either as standalone therapy or in combination with radiation, and development of conformal treatment devices.