Validation study of radio-guided sentinel lymph node navigation in esophageal cancer

BACKGROUND:: Radio-guided detection of sentinel lymph nodes (SLN) has been used to predict regional lymph node metastasis in patients with melanoma and breast cancer. However, the validity of the SLN hypothesis is still controversial for esophageal cancer. The aim of this study is to evaluate the feasibility and accuracy of radio-guided SLN mapping for esophageal cancer. METHODS:: Seventy-five consecutive patients who were diagnosed preoperatively with T1N0M0 or T2N0M0 primary esophageal cancer were enrolled. Endoscopic injection of technetium-99m tin colloid was performed before surgery and radioactive SLNs were identified with preoperative lymphoscintigraphy and gamma probe. Standard radical esophagectomy with lymphadenectomy was performed in all patients and all resected nodes were evaluated by routine pathologic examination. RESULTS:: SLNs were identified successfully in 71 (95%) of 75 patients. The mean number of identified SLNs per case was 4.7. Twenty-nine (88%) of 33 cases with lymph node metastasis showed positive SLNs. The diagnostic accuracy based on SLN status was 94% (67/71). Distribution of identified SLNs was widely spread from the cervical to abdominal areas. CONCLUSIONS:: This study reveals that radio-guided SLN mapping is an accurate diagnostic procedure for detecting lymph node metastasis in patients with early-stage esophageal cancer.