InSightec Ltd has submitted a premarket approval application (PMA) to the U.S. Food and Drug Administration (FDA) for its ExAblate treatment of pain palliation of bone metastases. Over 60% of cancer patients suffer from painful bone metastases and 30% of these patients will not respond to radiation therapy. ExAblate uses MR guided focused ultrasound (MRgFUS) to treat the pain caused by bone metastases non-invasively and without ionizing radiation. It combines high intensity focused ultrasound to thermally ablate tumors and continuous MRI to visualize the anatomy, plan treatment, and monitor treatment outcomes in real time. The PMA submission was based on a two-arm randomized controlled trial comparing patients undergoing ExAblate’s MR guided focused ultrasound for palliation of painful bone metastases with patients undergoing a sham treatment. Patients who had no response to the sham treatment were later allowedtoundergoanExAblatetreatment. Currently, ExAblate is the only MRgFUS system with FDA approval, which was granted in 2004 for uterine fibroids.