Fluorescence-guided surgery in colorectal cancer: current evidence, quantitative advances, and future perspectives

Fluorescence-guided surgery (FGS) has progressed from a qualitative adjunct to a quantitative, data-driven tool in colorectal surgery. Fluorescence-guided angiography for perfusion assessment shows mixed randomized results overall, with signals of benefit in low anterior resection and less-severe leaks; emerging metrics (e.g., time-to-peak, slope, time from the initial fluorescence increase to half of the maximum [T1/2MAX], time ratio [TR]) support objective decision-making. Fluorescence-guided lymphatic mapping can increase D3 yield, whereas consistent oncologic benefit remains uncertain; sentinel lymph node mapping in early colon cancer is feasible but not standard. In advanced rectal cancer, fluorescence may facilitate lateral pelvic node dissection with lower blood loss and selective clearance, though long-term outcomes require confirmation. Tumor-targeted imaging shifts FGS from anatomy to biology, aiding detection of occult disease, characterization of indeterminate lesions after therapy, and therapeutic decision-making for organ preservation. Near-infrared II (NIR-II) agents and hybrid positron emission tomography (PET)/NIR tracers promise deeper penetration and preoperative-to-intraoperative correlation but remain largely preclinical. Platform advances, automated data capture, tumor to background ratio thresholds, and artificial intelligence-assisted analytics are moving FGS toward integrated, reproducible workflows. Priorities include international standardization, prospective trials with long-term endpoints, validated tumor-targeted probes, and digital/robotic integration.