Ufoguide is a prospective single arm open study to assess the feasibility of a new type of HIFU system to treat bone tumors.

HIFU is classically delivered by a transducer integrated in the MRI table. This study assesses a new type of approach in which the HIFU transducer is manually placed on the skin of the patient, under the assistance of optical navigation, and held in place by MR-compatible passive arms.

The primary goal of this study is to assess the feasibility of heating the tumor accurately with this new HIFU system. The evaluation and monitoring of the treatment will be performed by MR thermometry.

Secondary endpoints include the evaluation of clinical efficacy, quality of life and safety.

Ufoguide is a prospective single arm open study to assess the feasibility of a new type of HIFU system for the treatment of painful metastases (palliative intent) and osteoid osteoma (curative intent).

HIFU is classically delivered by a transducer integrated in the MRI table. This study assesses a new type of approach in which the HIFU transducer is manually placed on the skin of the patient and held in place by MR-compatible passive arms. Optical infrared navigation is used to help the physician with the positioning of the HIFU transducer.

The primary goal of this study is to assess the feasibility of heating the tumor accurately with this new HIFU system. The evaluation and control of the treatment will be performed by Proton Resonance Frequency Shift (PRFS) MR thermometry.

Secondary endpoints include the evaluation of clinical efficacy, quality of life and safety.

Clinical efficacy is defined:

• in palliative intent by a decrease ≤3 on visual analogic scale
• in curative intent (osteoid osteoma) by a total disappearance of pain Quality of life is assessed by EORTC quality of life questionnaire-core 30 items Complications are recorded to assess safety.

Inclusion Criteria:

• Subject with one or more painful bone metastases (EVA≥5)
• Subject with sub-perolate or cortical osteoid osteoma
• For people with painful bone metastases: first-line treatment or radiotherapy failure
• Weight < 140kg.
• Target tumor accessible by HIFU-MRI
• Maximum size of the lesion - 20cm²
• Depth of the lesion to be treated - 4mm and 10cm
• Subject affiliated with a health insurance social protection.
• A subject capable of understanding research objectives and risks and giving informed and signed consent
• Subject who has been informed of the pre-medical visit results

Exclusion Criteria:

• MRI contraindication
• Contraindication to the use of a gadolinium contrast or hypersensitivity to gadoteric acid, meglumine or any drug containing gadolinium
• General anesthesia contraindication
• Non-reversible hemostasis disorders
• Previous injury on the area to be treated (radiotherapy, surgery, ...)
• Tumors located on the spine or skull
• Tumors located on the ribs
• Pathological fracture
• For Osteoid Osteoma: nidus more than 1cm deep within cortical bone
• Pregnant woman (pregnancy test, urinary or HCG dosage, negative to inclusion) or lactating
• existence of dermatological pathologies
• Subject with a known latex allergy
• Subject under safeguarding of justice, under guardianship or curatorship
• Subject in an exclusion period by a previous or ongoing study