The treatment consists of tumor ablation by Ablathermy Focused Ultrasound (USF), guided by MRI, performed under local anesthesia and sedation.

The treatment consists of tumor ablation by USF, guided by MRI, performed under local anesthesia and sedation. Patients will be operated (mastectomy) from 48 hours after ablation.

Inclusion Criteria:

• Invasive Breast Carcinoma with histologically confirmed hormone receptor analysis, the grade of the tumor, the expression of Her-2.
• Lesion classified T1-T2-T3 unifocal or multifocal with or without associated microcalcifications
• Lesion recognizable and identifiable in MRI
• Indication of mastectomy with or without axillary
• Lesion located more than 10 mm from the skin, the nipple and pectoralis major
• No cons-indication to MRI (pacemaker)
• Women whose age is ≥ 18 years
• If premenopausal patient: patient contraceptives
• Patient has signed informed consent
• Affiliation to a social security scheme

Exclusion Criteria:

• Tumor-TD T4B classified or non-palpable lesion
• If age <70 years: no indication of adjuvant chemotherapy and neoadjuvant
• MRI lesions have not been identified, located within 10 mm of the skin and pectoral muscle, greater than 25 mm diameter
• Inability to hold still in the prone position, arms extended, for 30 minutes
• Contraindication to MRI
• Patient deprived of liberty and major subject of a measure of legal protection or unable to consent
• Patient participating in another interventional clinical trial within 30 days prior to baseline and during the trial.