During the treatment procedure, an intravenous catheter will deliver MR contrast media and medications (such as sedation and analgesics if required) within the MR room. The body temperature of the patients will be measured prior to the procedure. In the MR room the patients will lie still on the HIFU patient table inside the MRI magnet. The operator will locate the target tissue and mark the volume to be treated using MRI images. The operator starts the treatment and monitors the progress of the treatment with MR thermal and dose maps according to the Sonalleve Instructions for Use to ensure safety. Following the MR-HIFU procedure, a set of MR images of the target region will be acquired with the use of a MR contrast agent, together with a functional brain MRI. The functional brain MRI is not clinical practice: it is not dangerous for the patient, it only involves a longer time of exam for the patient under the MRI tunnel. Patients will return for follow-up appointments on Day 14, 30, 60 and 90 for clinical examination. Clinical examination will include inspection and palpation of the treated area and assessment of functionality (e.g. walking pattern or range of movement). The Brief Pain Inventory and the EORTC-quality of life questionnaire will also be administered (to be completed by the patient), and pain medication usage and any possible adverse events will be recorded. Additionally, bone MRI of the treated site and functional brain MRI images will be acquired at 30 and 90 days after treatment.