R0, the new grail — how multimodal molecular imaging, mixed reality, and artificial intelligence contribute to 100% effective surgery

Achieving microscopically negative margins (R0) remains one of the main challenges in breast-conserving surgery (BCS), directly influencing local control, cosmetic outcome, and the need for re-excision. Despite advances in localization techniques such as seed placement and intraoperative pathology, incomplete resections still occur in up to 20% of cases. Recent technological developments now offer the opportunity to redefine margin assessment through multimodal intraoperative molecular imaging,