Clinical Research Directory

Inclusion Criteria: 1. Women 2. Age \> 60 years 3. Postmenopausal (no menstrual period for at least 12 months or in case of an intra-uterine device (IUD) hormone levels that indicate the menopause: follicle stimulating hormone (FSH) \> 20 IE/l and estradiol \< 100 pmol/l) 4. Histopathological confirmed primary invasive ER+/HER2- type breast cancer 5. Bloom Richardson grade 1 or 2 (low or intermediate malignancy grade) 6. Unilateral and unifocal breast cancer 7. A clinical T1N0M0 tumor (≤ 2cm and N0 on US and/or MRI), without distant metastases. The largest diameter measured will be used to determine eligibility. 8. Tumor should be visible and well delineated (all borders of the tumor should be visible) on ultrasound at diagnosis and during the procedure. 9. Sufficient knowledge of the Dutch language to complete the questionnaires 10. To be able to give written informed consent Exclusion Criteria: 1. History of invasive breast cancer 2. Breast augmentation 3. BRCA-1 or 2 gene mutation carrier 4. Lobular carcinoma 5. Triple negative breast cancer 6. Multifocality 7. HER2-neu overexpressing tumors 8. Lymph vascular invasion (LVI) on core needle biopsy or histopathological confirmed after lumpectomy 9. Indication for neoadjuvant systemic therapy 10. Intraductal component \> 25% of the diameter of the invasive tumor on MRI, complete area of the primary tumor should not exceed 2cm. 11. Allergic to local anesthetics 12. Electrical devices and/or implants that are not compatible with MRI 13. Current severe breast infection 14. Uncorrectable coagulopathy 15. Hemodynamic instability 16. Respiratory instability 17. Refraining from adjuvant radiotherapy 18. Indication for oncoplastic surgery (surgical volume replacement techniques e.g. LICAP)