Mapping sentinel nodes in patients with early-stage gastric carcinoma.

Background: Nodal status in gastric carcinoma is related not only to prognosis but also to the extent of nodal dissection. However, a method for accurate assessment of nodal status during operation has not been established. This study aimed to map the sentinel nodes of gastric carcinoma and to estimate the clinical usefulness of sentinel node biopsy.

Methods: Following laparotomy, a vital dye (0.2 ml 2 per cent patent blue) was injected through a gastroscope into the submucosal layer at four sites around a clinical T1 gastric carcinoma. The dye immediately appeared at the serosal surface and stained lymphatic vessels and nodes. The stained nodes were removed and examined by frozen sectioning.

Results: The assay was successful in mapping the lymphatic basins in 203 (96.2 per cent) of 211 patients. The dye stained one or more metastatic nodes in 31 patients, but failed to indicate a metastatic node in four patients with a large involved node. Meticulous postoperative examination of all resected nodes in the standard paraffin slices revealed no new metastases. The accuracy of the assay was 98.0 per cent.

Conclusion: The method was accurate in predicting nodal status in patients with early-stage gastric carcinoma.