Objective: The one-step nucleic acid amplification (OSNA) method has emerged as a potential alternative to ultrastaging for diagnosing lymph node metastasis. This study aims to assess the cost-effectiveness of the OSNA technique compared to ultrastaging for detecting SLN metastasis in patients with early-stage endometrial cancer (EC). Methods: This retrospective, observational, single-center study included 30 patients with EC who underwent surgical treatment. SLN mapping was performed using an intracervical injection of indocyanine green. SLNs were analyzed and classified as negative, as having isolated tumor cells, micrometastases, or macrometastases. The study evaluated and quantified the costs of the OSNA and ultrastaging procedures in euros. Results: A total of 54 lymph nodes were analyzed using both the OSNA and ultrastaging methods. Concordant negativity was identified in 48 cases (89 %), while micrometastases were detected concordantly in 1 case (1.8 %). The cost for a single ultrastaging lymph node analysis, including immunohistochemistry, is approximately € 250, with a total processing time of 2 days. The cost for a single OSNA analysis is approximately € 236, boasting a significantly shorter processing time of 30–40 min. While materials and staff costs are comparable between both techniques, considering time-related expenses, the OSNA method proves to be more cost-effective than ultrastaging (p < 0.001). Conclusions: The OSNA method demonstrates diagnostic accuracy comparable to histopathological examination in detecting lymph node metastases, reinforcing its reliability for lymph node assessment in patients with EC. Our cost analysis reveals that the OSNA method is more cost-effective than ultrastaging when time-related expenses are considered.
