In the case of a patient undergoing total mastectomy for intraductal carcinoma (DCIS), the sentinel lymph node is not excised during the primary surgery but only marked for identification. If the final histological examination confirms invasive cancer, delayed surgery is performed to remove the sentinel lymph node that was marked during the initial surgery. primary endpoint : The success rate of identifying the sentinel lymph node that was marked during the primary surgery in cases where the final histological examination confirms invasive cancer is evaluated. addendum) The previously documented Breast-Conserving Surgery has been corrected to reflect the accurate procedure of Total Mastectomy.