Sentinel lymph nodes with technetium-99m colloidal rhenium sulfide in patients with esophageal carcinoma

BACKGROUND: The authors assessed the detection of sentinel lymph nodes in patients with esophageal squamous cell carcinoma (SCC) using technetium-99m colloidal rhenium sulfide. They studied whether an analysis of sentinel lymph nodes using cytokeratin (CK) immunohistochemistry increased the accuracy of staging. METHODS: The authors observed 25 patients with thoracic esophageal carcinomas who underwent radical esophagectomy. The day before surgery, technetium-99m colloidal rhenium sulfide was injected into the submucosa at four sites around the primary tumor. Lymphoscintigraphy was performed. Esophagectomy and regional lymph node dissection were performed 17 hours after the technetium-99m injection. After surgery, the resected lymph nodes were evaluated by CK staining. RESULTS: Lymphoscintigraphy detected sentinel lymph nodes in 92% of the patients (23 of 25 patients). The accuracy of sentinel lymph node was 91.3% (21 of 23 patients), the sensitivity was 86.7% (13 of 15 patients), and the false-negative rate was 8.7% (2 of 23 patients). A comparison of the number of sentinel lymph nodes and clinicopathologic factors showed that there was a significant association between the number of sentinel lymph nodes and lymph node status (P < 0.01), pathologic stage (P < 0.05), and the number of metastatic lymph nodes (P < 0.05). Occult metastasis was detected by CK staining in 14 (56%) of the 25 patients and in 23 (1.7%) of 1406 lymph nodes. Because the 2 false-negative (sentinel lymph node-negative and nonsentinel lymph node-positive) patients who had occult metastases in the sentinel lymph nodes, the accuracy of sentinel lymph node evaluation using CK staining was 100% (23 of 23). CONCLUSIONS: Lymphatic mapping with technetium-99m colloidal rhenium sulfide was used to identify the lymphatic basin and was feasible in patients with esophageal SCC. An analysis of sentinel lymph nodes using CK immunohistochemistry increased the accuracy of sentinel lymph node.