Indocyanine Green-Guided Lateral Pelvic Sentinel Lymph Node Mapping in Low Rectal Cancer: Toward a Selective Alternative to Systematic Sidewall Lymphadenectomy

The management of advanced low rectal cancer is shaped by an ongoing tension between two surgical philosophies regarding lateral pelvic lymph node (LPLN) disease. Eastern and Western guidelines diverge on whether systematic lateral lymph node dissection (LLND) should accompany total mesorectal excision (TME), reflecting different views of the locoregional behavior of LPLN involvement and different thresholds for accepting the urinary and sexual morbidity that accompanies full sidewall clearance. In this editorial, we argue that intraoperative interrogation of each individual case offers a way to refine, rather than resolve by regional consensus, this geography-driven dichotomy, and that indocyanine green (ICG) near-infrared fluorescence provides a principled means of individualizing the extent of lateral dissection. Peritumoral submucosal injection of ICG enables real-time visualization of lymphatic drainage and intraoperative identification of lateral pelvic sentinel lymph nodes (LPSLNs), which can be biopsied and submitted for frozen section. It is important to distinguish between the two applications of this signal. As an intraoperative visualization adjunct, ICG improves lateral node retrieval, and the supporting comparative evidence is relatively consistent. As a sentinel-based decision tool for safely omitting lateral dissection when the sentinel node is negative, the concept is promising but rests on a smaller and less mature evidence base; it remains investigational and requires validation in larger prospective studies with long-term oncologic and functional outcomes before it can guide the omission of lateral dissection in practice. We outline the operative protocol used in our department, extended from sentinel node mapping for gynecological malignancies, and place it in the context of contemporary systematic, propensity-matched, and prospective sentinel biopsy series. In our view, fluorescence-assisted selective LLND may serve as a pragmatic bridge between existing paradigms, preserving the oncologic intent of Japanese-style lateral clearance while aligning with Western priorities of minimizing unnecessary morbidity through tailored, image-guided surgery.