Consensus on the regional lymph nodes irradiation in breast cancer.

Standard locoregional treatment of early-stage breast cancer currently consists of the conservative surgery and sentinel lymph node biopsy. In the event of positive sentinel node biopsy, an axillary level I-II lymphadenectomy should be carried out. However, recent publications have increasingly supported a tendency not to apply the surgical lymphadenectomy, but simultaneously, it has been developed a new role of regional radiotherapy, even if there is only 1-3 axillary lymph nodes involved. Given these new trends, radiation oncologists are facing the dilemma with regard to deciding about regional irradiation of breast cancer. For such purpose, The Spanish Group of Breast Cancer Radiation Oncology (GEORM as per its Spanish acronym) decided to reach a consensus to issue the respective guidelines for such types of cases. GEORM Managing Commission, gathering 13 members of different Spanish regional communities, issued a questionnaire including different clinical situations. These questions were set as key questions seeking responses, which were answered by 66 % out of the 75 members of the group. Following the response, the guidelines were drafted based on the replies to the mentioned questionnaire. All the respective issues were discussed by means of a virtual platform. In this article, we show the levels of consensus for different clinical situations, depending on the number of nodes involved and the type of surgical procedure performed on the axillary lymph nodes. The ongoing evolution of the oncological treatments obliges the radiation oncologists to take decisions without any existing clarifying evidence, and therefore, the consensus is necessary, which can assist in the decision-making process by the practitioners in such kinds of clinical situations.