Intraoperative Techniques That Define the Mucosal Margins of Oral Cancer In-Vivo: A Systematic Review

Simple Summary This systematic review evaluates techniques defining adequate mucosal margins during the resection of oral squamous cell carcinoma (SCC). Residual SCC and dysplasia demand distinct adjuvant treatment, such as re-resection and radiation for SCC or CO2-laser evaporation for severe dysplasia, necessitating accurate differentiation between SCC and dysplasia during surgery. The study includes eight investigations into margin visualization techniques-autofluorescence, iodine staining, and narrow-band imaging-concluding that, except for autofluorescence, there is considerable variability in negative predictive values. Autofluorescence does not significantly enhance margin outcomes compared to conventional white light-guided surgery, while iodine does. Studies on narrow-band imaging did not report a comparison with a white light-guided surgery cohort. The review advocates for more comprehensive studies comparing the diagnostic accuracy of iodine staining or narrow-band imaging, with a specific focus on diagnostic accuracy and the discrimination between SCC and dysplasia.Abstract Background: This systematic review investigates techniques for determining adequate mucosal margins during the resection of oral squamous cell carcinoma (SCC). The primary treatment involves surgical removal with >= 5 mm margins, highlighting the importance of accurate differentiation between SCC and dysplasia during surgery. Methods: A comprehensive Embase and PubMed literature search was performed. Studies underwent quality assessment using QUADAS-2. Results: After the full-text screening and exclusion of studies exhibiting high bias, eight studies were included, focusing on three margin visualization techniques: autofluorescence, iodine staining, and narrow-band imaging (NBI). Negative predictive value (NPV) was calculable across the studies, though reference standards varied. Results indicated NPVs for autofluorescence, iodine, and NBI ranging from 61% to 100%, 92% to 99%, and 86% to 100%, respectively. Autofluorescence did not significantly enhance margins compared to white light-guided surgery, while iodine staining demonstrated improvement for mild or moderate dysplasia. NBI lacked comparison with a white light-guided surgery cohort. Conclusions: We recommend studying and comparing the diagnostic accuracy of iodine staining and NBI in larger cohorts of patients with oral SCC, focusing on discriminating between SCC and (severe) dysplasia. Furthermore, we advise reporting the diagnostic accuracy alongside the treatment effects to improve the assessment of these techniques.