Contemporary Indications and Technical Limits of Transoral Laser Microsurgery for Laryngeal Squamous Cell Carcinoma

Transoral laser microsurgery (TOLMS) is an established organ-preserving treatment for early-stage and selected intermediate-stage laryngeal squamous cell carcinoma (SCC). Initially indicated for Tis-T1 lesions, its use has progressively expanded to carefully selected T2 and T3 tumors, providing oncologic outcomes comparable to open surgery and (chemo)radiotherapy [(C)RT] while offering favorable functional results. The CO₂ (carbon dioxide) laser is the preferred device for TOLMS due to its precision and minimal thermal injury, allowing accurate tumor resection with optimal margin control. Successful application of TOLMS relies on strict patient selection and comprehensive pre- and intraoperative assessment. High-definition videolaryngoscopy, angled telescopes, bioendoscopic techniques, advanced imaging modalities, and emerging artificial intelligence tools have significantly improved the evaluation of tumor extent, biological behavior, and laryngeal function. Adequate laryngeal exposure is a critical prerequisite, as difficult exposure is associated with higher rates of positive margins and inferior oncological outcomes. Preoperative imaging, particularly magnetic resonance imaging (MRI) and dual-energy computed tomography (CT), is essential for assessing deep tumor extension, cartilage invasion, and involvement of key anatomical subsites, including the anterior commissure (AC), paraglottic space (PGS), and pre-epiglottic space (PES). AC involvement alone is not an absolute contraindication to TOLMS; however, vertical trans-AC extension and posterior PGS invasion, especially when associated with arytenoid fixation, represent major limitations due to the difficulty in achieving adequate oncologic margins. Surgical margin assessment remains challenging because of specimen shrinkage and variability in pathological evaluation, yet positive margins-particularly deep or multiple-are associated with worse disease-specific survival and laryngeal preservation. In supraglottic SCC, TOLMS is feasible for T1-T2 and selected T3 tumors, although functional outcomes decline with increasing extent of resection and patient age. The role of TOLMS in the salvage setting is limited and requires highly selective indications. In conclusion, TOLMS is an effective treatment for appropriately selected laryngeal cancers, provided that meticulous diagnostic work-up, surgical expertise, and multidisciplinary decision-making are ensured.