Aim: This study aims at evaluating the performances of an intraoperative gamma camera (field of view 10X10 cm), named CarolIReS, to detect axillary drainage and to assess the removal of sentinel lymph nodes (SLN) in breast surgery. Patients and Methods: SLN biopsy will be performed on 110 patients and the CarolIReS camera will be used preoperatively to localize SLNs. During surgery, individual removal of SLNs will be performed using a gamma probe named CarolIReS and their activity will be measured with a gamma ray counter. At the end of surgery, the CarolIReS camera will be used again to check the quality of surgery which will be followed by a surgical excision in case of remaining SLNs. Objectives: The main objective of this study is to evaluate the performances of the CarolIReS camera in assessing the axillary drainage of breast tumors and the surgical removal of SLNs. In addition, the possible correlation between the activity, the size, and the metastatic involvement of the SLNs will also be studied.Study hypothesis: Intraoperative cameras could be used to improve the efficiency of the SLN procedure