Local management of second ipsilateral breast cancer events after primary breast-conserving therapy: an international Delphi consensus

An international Delphi consensus involving 36 multidisciplinary panellists from US and European oncology societies established expert agreement on patient selection and local treatment strategies for second ipsilateral breast cancer events (iBCEs) after prior breast-conserving therapy. The panel, comprising radiation oncologists, breast surgeons, a plastic surgeon, and medical physicists, completed two rounds of structured questionnaires to address the controversial management of these recurrences. The resulting guidance, endorsed by major surgical and radiation oncology societies, aims to standardise clinical decision-making in an area where robust trial data remain limited.