Cost-Effectiveness of [^99mTc]Tilmanocept Relative to [^99mTc]Sulfur Colloid for Sentinel Lymph Node Biopsy in Early Stage Oral Cavity Cancer

Background: Several studies have demonstrated varying rates of efficacy, reliability, and sensitivity of sentinel lymph node biopsy (SLNB) in identifying occult nodal disease for early stage oral cavity squamous cell carcinoma (OCSCC) depending on the radionuclide agent utilized. No head-to-head comparison of cost or clinical outcomes of SLNB when utilizing [^99mTc]tilmanocept versus [^99mTc]sulfur colloid has been performed. The goal of this study was to develop a decision model to compare the cost-effectiveness of [^99mTc]tilmanocept versus [^99mTc]sulfur colloid in early stage OCSCC. Patients and Methods: A decision model of disease and treatment as a function of SLNB was created. Patients with a negative SLNB entered a Markov model of the natural history of OCSCC parameterized with published data to simulate five states of health and iterated over a 30-year time horizon. Treatment costs and quality-adjusted life-years (QALYs) for each health state were included. The incremental cost-effectiveness ratio (ICER) was then estimated using $100,000 per additional QALY as the threshold for determining cost-effectiveness. Results: The base case cost-effectiveness analysis suggested [^99mTc]tilmanocept was more effective than [^99mTc]sulfur colloid by 0.12 QALYs (7.06 versus 6.94 QALYs). [^99mTc]Tilmanocept was more costly, with a lifetime cost of $84,961 in comparison with $84,264 for sulfur colloid, however, the overall base case ICER was $5859 per additional QALY, well under the threshold for cost-effectiveness. Multiple one-way sensitivity analyses were performed, and demonstrated the model was robust to alternative parameter values. Conclusion: Our analysis showed that while [^99mTc]tilmanocept is more costly upfront, these costs are worth the additional QALYs gained by the use of [^99mTc]tilmanocept.