[en] The sentinel lymph mode (SLN) technique in breast cancer is aimed to avoid useless axillary lymph node dissection (ALND). We present here our experience in a series of 42 patients. After some protocol evolutions imposed by the first results, 37 patients were similarly studied: 4 to 6 peritumoral injections (0,75 ml sulfur colloid labeled with ^99mTc) were immediately followed by local gentle massage for 5 min, and then by dynamic imaging (anterior and lateral simultaneously) in prone decubitus with pending breast. Then the SLN was skin-land-marked in surgical position (dorsal decubitus) in two incidences (typically anterior and lateral); SLN localisation on ventral decubitus images directed additional actions as necessary: pulling the breast, oblique incidence. Upon surgery, after primary lesion malignancy confirmation, the SLN was electively dissected and then the usual ALND was performed. If we exclude from analysis the 4 cases of previous lumpectomy (among which we had one total lack of tracer migration and one prediction error), the final diagnostic results were perfect: lympho-scintigraphic and per-operative SLN detection were 100%, predictive error was 0%. This result seems to be mainly due to prone decubitus imaging which moves away peritumoral activity from axilla and thus makes easier final land-marking in dorsal decubitus. (author)