Table 1.

General inclusion and exclusion criteria for osteoid osteoma MRgFUS treatment

Inclusion criteria • Age ≥5 years • Subject able to give informed consent or subject assents with informed consent from parent or guardian • Weight <140 kg (requirement to fit safely on top of the MRgFUS table and inside the MR magnet) • Definitive radiographic and clinical presentation of an osteoid osteoma   o OR biopsy proven osteoid osteoma when clinical or imaging findings are inconclusive • Pain specifically at the site of interest (target lesion) • Pain intensity (for the target lesion) in the moderate to severe range as measured by age-appropriate validated pain assessment tools. • Target lesion is uncomplicated (no fracture/spinal cord compression/cauda equina syndrome/soft tissue component) • Target lesion maximum dimension ≤3 cm (otherwise lesion may not be an OO) • Target lesion visible by noncontrast MRI • Target lesion accessible for MRgFUS procedure • MRgFUS treatment date ≥2 weeks from most recent surgical/radiologic treatment of osteoid osteoma Exclusion criteria • Unable to characterize pain specifically at the site of interest (target lesion) • Pregnant female • Target lesion is complicated (presence of one of fracture/soft tissue component). • Target lesion <1 cm away from the skin, neurovascular bundles, bowel, hollow viscera, or regions of cartilage/ bone growth plate • Target lesion located in the skull and spine (excluding sacrum) • Inability to position area of interest on the MRgFUS transducer • Scar along proposed MRgFUS beam path or unable to exclude scar from path • Orthopedic implant along proposed MRgFUS beam path or at site of target lesion • Serious cardiovascular, neurological, renal, or hematological chronic disease • Active infection • Contraindication to deep sedation/general anesthesia or MRI • Contraindication to gadolinium (nursing mothers, renal failure, etc.) is a relative contraindication to the procedure. MRgFUS can still be performed but perfusion information would not be obtained.