CT or EUS for the initial staging of esophageal cancer? A cost minimization analysis

Background: Patients with advanced (T4 and/or M1) esophageal cancer are off ered palliative therapy. Computed tomography (CT) is sensitive for distant metastases but is less sensitive than endosonography for T4 disease and cel iac lymphadenopathy. The aim of this study was to determine whether initial CT or endosonography costs less to diagnose advanced esophageal cancer. Methods: A decision model compared the costs of the 2 strategies. Sensitivi ty analysis and threshold analysis were used to identify the most important determinants of the overall cost of identifying advanced disease. Results: Initial CT is the least costly strategy if the probability of find ing advanced disease by initial CT is greater than 20%, if the probability of finding advanced disease by initial endoscopic ultrasound (EUS) is less than 30%, or if the cost of EUS is greater than 3.5 times the cost of CT. H owever, in our referral center population, endosonography found advanced di sease more frequently than CT (44% vs. 13%; p < 0.0001) and the least costl y strategy was initial endosonography (expected cost $804 vs. $844). Conclusion: CT remains as the initial staging test of choice in most clinic al settings. However, in referral centers, initial EUS may be reasonable, b ut individualized model inputs must be obtained before reliable conclusions can be drawn.