Breast cancer is the most common invasive cancer in women worldwide. Many women with breast cancer have their malignant tumors detected before the lesions become clinically palpable. Occult lesions must be marked for the surgeon to ensure that they can be effectively resected. Image-guided wire localization (WGL) is the current standard of care for the excision of non-palpable carcinomas during breast conserving surgery. The integration of the information from multimodal imaging may be especially relevant in surgical planning as complement or an alternative to WGL. The combination of information from images in different positions is especially difficult due to large breast deformation. This work presents a system based on surface registration to localize the lesion in the operative position, starting from a prone MRI study and a surface of the patient in the supine positon. The pre-operative surface from the MRI is registered to the surface obtained in a supine position similar to the intraoperative setting. Triangular meshes have been used to model breast surface in both positions and surfaces are aligned using a Laplacian deformation with fiducials automatically obtained from 3 anatomical references. The evaluation of the methodology has been carried out in 13 cases in which a supine- CT was available achieving an average localization error of 6.7 m
