Efficacy of MR-HIFU Ablation of Breast Cancer

Inclusion Criteria: * Women, aged 18 years and older. * Able to give informed consent herself. * World Health Organization (WHO) performance score ≤ 2. * Biopsy proven cT1-2 N0-2 MX invasive breast cancer with a size of ≤ 3.0 cm. * Histological type of tumor: invasive ductal carcinoma (IDC), not otherwise specified (NOS) or no special type (NST). * The target breast fits in the cup of the dedicated MR-HIFU breast system. * Patient weight is limited to ≤ 90 kg, because of restrictions to the HIFU table top. Additional inclusion criteria based on DCE-MRI findings: * The distance of the tumor, including a 5 mm margin around the tumor, from the skin, nipple and pectoral wall is at least 1.0 cm measured on MRI. * The tumor is located within the reach of the HIFU beam produced by the transducers in the HIFU breast system. Exclusion Criteria: * Prior treatment with: neo-adjuvant systemic therapy in the past 3 months or radiotherapy or thermal therapy or surgery of any kind in the targeted breast. * Contraindications to MR imaging according to the hospital guidelines (e.g. pacemaker in situ, severe claustrophobia, big metal implants, body size incompatible with MR bore). * Contraindications to administration of gadolinium-based contrast agent, including: prior allergic reaction to a gadolinium-based contrast agent, kidney disease (e.g. nephrogenic systemic fibrosis, nephrogenic fibrosing dermopathy) and/or renal failure (GFR \< 30 ml/min/1,73m2). * Contra-indications for procedural sedation analgesia with Propofol and Esketamine or Propofol and Remifentanil. * Extensive intraductal components in the lesion determined by biopsy. * Scar tissue or surgical clips in the HIFU beam path. * Inability to lie in prone position. * Pregnancy or lactation. * Communication barrier with patient. The following groups of patients will be excluded because the risk of adjuvant over- or undertreatment due to performing the Bloom and Richardson (B\&R) grading on the tumor biopsy is considered to high: * N0, Her2neu negative, \<35 years, ≤1cm (T1a/b) with B\&R grade 1 or 2 on biopsy. * N0 Her2neu negative, ER/PR negative (triple negative), 35-70yr, 1.1-2cm (T1c) with B\&R grade 1 or 2 on biopsy. * N0, Her2neu negative, ER/PR positive \> 50%, ductal carcinoma, 60-70yr, 1.1-2cm (T1c), with B\&R grade 3 on biopsy and if the MammaPrint is not reimbursed by health insurance also for grade 1 on biopsy. * N0, Her2neu negative, ER/PR positive, ductal carcinoma, 35-60yr, 1.1-2cm (T1c) with B\&R grade 1 on biopsy. * N0, Her2neu negative, ER/PR positive, but ≤50%, ductal carcinoma, 60-70yr, 1.1-2cm (T1c) with B\&R grade 1. The following group of patients will be excluded based on the results of the MammaPrint: • Only if the MammaPrint is reimbursed by health insurance: N0, Her2neu negative, ER/PR positive, \> 50% ductal carcinoma, 60-70yr, 1.1-2cm (T1c), with B\&R grade 1 and MammaPrint high risk.