District of Columbia
This study looks to examine the feasibility and efficacy of using MR-HIFU to ablate Osteoid
Osteoma lesions in children and young adults.
Osteoid Osteoma (OO) is a benign, but painful, bone tumor commonly occurring in children and
young adults. Common treatment options are surgical excision or, more recently, CT-guided
radiofrequency ablation (RFA). RFA is less invasive, but it still requires drilling from the
skin through muscle and soft tissue into bone. It also exposes the patient and operator to
Magnetic Resonance guided High Intensity Focused Ultrasound (MR-HIFU) provides precise and
controlled delivery of focused ultrasound energy inside a lesion using an external
applicator, without the need for a scalpel or needle. MR-HIFU has been successfully used to
treat painful bone metastases in adult clinical trials and one recent report suggests that it
can also be used to treat OO.
MR-HIFU ablation of OO may provide a better alternative to surgical resection or RFA as it is
completely non-invasive and does not require ionizing radiation. These two qualities of
MR-HIFU are especially beneficial in growing children and young adults. Furthermore, MR-HIFU
OO ablation is quick, with expected total procedure time of less than two hours. Such short
treatments offer additional safety benefits from reduced anesthesia / sedation requirement
compared to surgery and RFA
- All patients with a clinical suspicion of OO based on presence of typical
symptoms of localized nocturnal pain that is relieved by NSAIDs and unrelated to
trauma or activity.
- Typical imaging findings on CT and/or MRI. Plain radiographs and bone scans may
be obtained by referring physicians and are helpful for confirming the clinical
diagnosis but cannot be substituted for a CT or MRI.
- Non-contrast enhanced or contrast enhanced CT studies are acceptable.
- Contrast enhanced MRI studies should be performed.
- Tissue biopsy is not required
- Tumor location:
- Target lesions can be located in any peripheral bone with acoustic accessibility.
- Target lesions may be intracortical or juxtacortical in location.
- Target lesions must be reachable within the normal safety margins of HIFU as
specified in the instructions for use.
- Prior therapy:
●Patients with prior unsuccessful surgical resection or RFA are eligible for
- Laboratory :
- Hemoglobin > 9 g/dL
- Platelet count ≥75,000/µL (may receive transfusions)
- Normal PT, PTT and INR < 1.5 x ULN (including patients on prophylactic
- Renal function: Age-adjusted normal serum creatinine (table in protocol) OR a
creatinine clearance ≥60 mL/min/1.73 m2 for safe contrast administration
- Adequate pulmonary function: Defined as no dyspnea at rest, and a pulse oximetry >94%
on room air if there is clinical indication for determination.
- Clinically significant unrelated systemic illness, such as serious infections,
hepatic, renal or other organ dysfunction, which in the judgment of the Principal or
Associate Investigator would compromise the patient's ability to tolerate the general
anesthetic required for the procedure.
- Implant or prosthesis or scar tissue within the path of the HIFU beam.
- Target <1 cm from nerve plexus, spinal canal, bladder, bowel
- Target <1 cm of the growth plate (physis)
- Lesion in the skull or vertebral body
- Inability to undergo MRI and/or contraindication for MRI
- Inability to tolerate stationary position during HIFU
- Patients currently receiving any investigational agents.