Cost Analysis of Sentinel Lymph Node Biopsy for Oral Tongue Squamous Cell Carcinoma: Institutional Cohort and Population-Based Simulation.

Introduction: In oral carcinoma patients classified as cN0, selective neck dissection (SND) and sentinel lymph node biopsy (SLNB) may be used to stage the neck with equivalent oncological results. Objective: Compare the costs of SLNB and SND for oral squamous cell carcinoma. Methods: Analysis of institutional cohort and Markov chain model simulation using populational data. Results: We included 84 patients submitted to transoral resection and SLNB or SND and patients submitted only to SND. The mean cost was R$4,943,67 for SLNB and R$ 11,005.49 for SND with significant differences in length of stay (one versus three days, p < 0.001), operative time (92 versus 177 minutes, p < 0.001) and postoperative hospital visits in 60 days (two versus eight, p < 0.001). For the simulation model, the probability of not finding the SLN ranged from 0.0% to 5.7% with 0.5% increments and the probability of occult neck metastasis ranged from 9.0% to 100.0% with 1% increments. The costs of SLNB increase progressively as the rate of occult neck metastasis increases. When this rate reaches 56%, the cost difference becomes not significant. With rates above 72%, SLNB becomes significantly more expensive than SND. Using a public database, we calculate a cost decrease ranging from 27.93% to 66.54% with SLNB adoption. Conclusion: SLNB adoption may significantly decrease the costs associated with early-stage oral cancer treatment. It would allow more patients to be treated with the same number of resources now available.