 Despite the advancement and increasing use of nipple-sparing mastectomy NSM is still carried out in a portion of breast cancer patients. However, the role of NSM is still controversial, mainly because of concern about the oncologic safety of the nipple-areola complex NAC. Radiation therapy uses high-energy x-rays to damage tumor cells. Giving radiation during surgery followed by external-beam radiation to the entire breast may kill more tumor cells.INTRABEAM Carl Zeiss, Oberkochen, Germany is the most widely used mobile intraoperative radiotherapy IORT device to date. This study aims to broaden the application of the INTRABEAM system for breast cancer, investigating the feasibility of INTRABEAM IORT in NSM with breast reconstruction. 