Group I : The SLN procedure will be initiated 18 hours before surgery using a preoperative injection of colloidal rhenium sulphur and technetium (0.4 ml, 20 MBq of Nanocis®; CIS Bio International, France) at the four cardinal points in the subareolar area. Lymphoscintigraphy will be obtained 3 hours after the injection. Immediately before surgery, the axillary drainage will be checked using the CarolIReS camera (FOV 10x10 cm²). During surgery, the search for radioactive nodes will be performed using the CarolIReS probe. In order to evaluate the CarolIReS camera sensitivity, the activity of the removed SLNs will be measured immediately after their resection by a gamma ray counter and they will then be submitted to pathological analysis with frozen section.