Intraoperative NIR-II fluorescence guidance for precise tumor margin assessment and maximized tissue preservation in breast surgery

Background: Accurate margin assessment remains a challenge in breast-conserving surgery, where inaccuracy leads to excessive removal and compromised aesthetics. Although second near-infrared (NIR-II) fluorescence imaging offers high contrast, there is still a lack of clinically viable NIR-II equipment. Methods: We develop an innovative NIR-II fluorescence navigation platform based on indocyanine green (ICG) that enables rapid deployment, operation-friendly workflow, and precision-at-hand capability for intraoperative guidance. Thirty-seven patients were recruited with 1 mg/kg ICG injection 45 minutes before surgery. Image quality was evaluated using perception-based image quality evaluator (PIQE) score, while quantitative analyses of fluorescence, including tumor-to-normal tissue ratio (TNR) and signal-to-background ratio (SBR), together with histopathology and a multi-level reader study, were performed to assess tumor contrast and diagnostic performance. Results: Compared to conventional NIR-I imaging, our NIR-II system demonstrates performance with enhanced spatial resolution and a higher tumor-to-normal tissue ratio (4.383 ± 1.719 versus 3.154 ± 1.072, P < 0.0001) in 37 patients. The intraoperative NIR-II imaging demonstrates superior tumor detection sensitivity [90.63% (75.78%-96.76%) vs. 84.38% (68.25%-93.14%)], with 100% diagnostic accuracy in delineating malignant tumor margins. Ex vivo NIR-II imaging enables real-time, precise visualization of tumor margins and suggested its potential to reduce the volume of excision. (NIR-II–defined volume < NIR-I–defined volume < current resection volume). Through brief training, surgeons can effectively utilize NIR-II imaging, shortening the learning curve for young surgeons in tumor and margin assessment. Conclusion: This study demonstrates a clinically adaptable NIR-II imaging platform that expands intraoperative visualization without changing surgical workflow or adding operational burden, supporting standardized margin assessment and improved tissue preservation in breast surgery.