Magnetic Resonance guided Focused Ultrasound (MRgFUS) has demonstrated to be effective for pain control through thermally-induced cell death and periosteal denervation caused by cortical heating relative to acoustic energy absorption. There is also evidence that a high intensity focused ultrasound beam can penetrate through the cortical bone to the medullary space, producing thermal necrosis of cancer tissue. However, little is known about the potential effects of MRgFUS as first line therapeutic modality for pain palliation in skeletal metastases.

Our hypothesis sought to assess the clinical performance of MRgFUS primary treatment of painful bone metastases and determine the potential of this technique for local tumor control.

Unlike previous studies, in which patients were enrolled for MRgFUS treatment because of the failure of other therapies, our study will be conducted in patients not previously treated with EBRT to the targeted lesion.

This is an important new feature, especially given the advantages of MRgFUS, such as lack of ionizing radiation, the ability to conduct treatment on an outpatient basis and the possibility to repeat the treatment as necessary.

Inclusion Criteria:

• the presence of a known primary cancer and bone metastases confirmed by two or more imaging modalities;
• exhaustion or refusal of all other pain palliation methods including EBRT;
• confirmation of MRgFUS treatment feasibility at a preliminary MR planning examination (presence of an adequate acoustic window between the transducer, skin and target lesion and absence of bowel loops across the planned ultrasound path)

Exclusion Criteria:

• general contraindication to MR imaging (including pacemaker, ferromagnetic devices or implants)
• general contraindication to gadolinium-based contrast agents (intolerance and/or clinically proven chronic renal failure)
• general contraindication to general/epidural anesthesia or deep sedation