Introduction. Sentinel node biopsy is the gold standard in the diagnosis of lymph node basin lesions in breast cancer. Although the method has got a long history of its application, some practical issues related to its economic and social advantages and disadvantages remain unresolved.Aims. To consider the efficiency of approaches to the diagnosis and minimally invasive treatment in breast cancer, following the experience of sentinel node biopsy in Regional Clinical Oncological Hospital, Yaroslavl.Materials and methods. Th e present paper involves the analysis of 942 histories of breast cancer patients who have undergone surgical treatment at Regional Clinical Oncological Hospital, Yaroslavl. According to the study results, 16% of stage I and II patients had a change in the initial status of lymph node basins aft er pathoanatomical examination of the removed lymph nodes. Th is prompted a change in preoperative examination and appointment of MRI of breast and lymph regional outflow for 64 patients prior to planning a sentinel lymph node biopsy.Results and discussion. Magnetic resonance imaging data correlated with the results obtained aft er histological examination and served to determine the extent of surgical treatment, reducing the risks of reintervention and locoregional recurrence.Conclusion. Sentinel node biopsy is a method that combines high informativity, safety and economic benefits. However, in order to achieve greater patient focus, a comprehensive approach to preoperative examination and principle of cooperation in the choice of treatment strategy should be observed in all cases.