Magnetic resonance guided focused ultrasound surgery (MRgFUS) is an emerging technology that can non-invasively
heat and ablate targeted tissue utilizing ultrasound energy. Use of MR imaging for treatment guidance provides several
key advantages over more widely used ultrasound guidance for focused ultrasound ablation. MR allows for precise
targeting, detailed beam path visualization, real time non-invasive temperature measurement, and treatment feedback to
ensure therapeutic goals are achieved. In the realm of oncology, management of painful bone metastases is a common
and daunting clinical problem. The Insightec ExAblate System has been shown in phase I/II trials for treatment of bone
metastases to have an excellent safety profile and high rates of pain response. An international multi-center phase III
trial for patients with painful bone metastases or multiple myeloma who are not candidates for radiation therapy is
currently open. Patients are randomized 3:1 to MRgFUS or sham treatment with crossover to study treatment allowed
for sham failures. The primary study endpoint is assessment of pain control over 3 months following treatment. In
addition safety, quality of life, cost effectiveness analysis, and patient perceived clinical benefit are also being assessed.
Details of the MRgFUS system, technical and clinical therapeutic parameters, use of real time non-invasive MR
thermometry, and examples of patient treatments with use of MRgFUS to treat bone metastases will be discussed. New
directions in use of MRgFUS including an update on development of a new mobile applicator and integration of
MRgFUS in multimodality oncologic care will also be presented.