Sentinel node mapping for esophageal cancer

Abstract

4552 Background: Extended radical esophagectomy with three-field lymph node dissection has been recognized as a standard procedure for esophageal cancer in Japan, even for clinically node negative cases. However, a significant increase of morbidity and mortality after the invasive procedure was reported in randomized trials. To eliminate the uniform application of highly invasive surgery, we hypothesized that sentinel node (SN) mapping plays a key role to obtain individual information and allows modification of the surgical procedure for early esophageal cancer. Methods: We have established radio-guided method to detect SNs in patient with early esophageal cancer using endoscopic injection of technetium-99m tin colloid. Preoperative lymphoscintigraphy and intra-operative use of hand held gamma probe were reliable to locate the radioactive SNs. Intra-operative gamma probing was also feasible in thoracoscopic or laparoscopic surgery using a special gamma detector which is introducible from trocar ports. Results: SN mapping has been performed for 105 patients with clinically N0 early esophageal cancer in our institute since 1999. Detection rate of hot node using our procedure was 93% (98/105). The mean number of sentinel nodes per case was 5.1. Thirty-three of 37 cases with lymph node metastasis showed positive sentinel nodes. The sensitivity to detect metastasis based on SN status was therefore 89% in our experience. Accuracy of metastatic status based on SN was 96% (94/98). SNs widely spread from cervical to abdominal areas. In more than 80% of the cases, at least one SN was located in the 2nd or 3rd compartment of regional lymph nodes. Conclusions: Our results suggest that SN concept for clinically N0 early esophageal cancer could be validated, and individualized selective and modified lymphadenectomy targeted on sentinel node basins for clinically N0 early esophageal cancer should become feasible and clinically useful as less invasive surgical procedures. No significant financial relationships to disclose.