Efficacy of different technical procedures for sentinel lymph node biopsy in gastric cancer staging

The clinical impact of sentinel lymph node biopsy (SLNB) in gastric cancer is controversial. We performed a prospective trial to compare different methods: radiocolloid method (RM), dye method (DM), and both methods simultaneously (dual method, or DUM) for reliability and therapeutic consequences.

RM and DM were applied in 35 gastric cancer patients. After endoscopic peritumoral injection of (99m)Tc-colloid and Patent Blue V, the positions of all blue sentinel lymph nodes (SLNs) were recorded, and the SLNs microscopically examined by hematoxylin and eosin, step sections, and immunohistochemistry.

RM, DM, and DUM identified the SLNs in 34 (97%) of 35 patients. The sensitivity for the prediction of positive lymph node status for RM was 22 (92%) of 24, for DM 16 (66%) of 24, and for DUM 22 (92%) of 24. In 7 of 17 (RM), 5 of 15 (DM), and 7 of 17 (DUM) patients classified as N0 by routine hematoxylin and eosin staining, micrometastases or isolated tumor cells were found in the SLN (upstaging) after focused examination. If only a limited lymph node dissection of the SLN basins would have been performed in patients, residual lymph node metastases were left in 9 of 24 (RM), in 7 of 34 (DM), and in 5 of 24 (DUM) of patients with node-positive disease.

Use of RM was superior. DUM did not further increase the sensitivity. A limited lymph node dissection-i.e., lymphatic basin in patients with SLN-positive disease-is associated with a high risk of residual metastases. Patients with negative SLNs may be selected for a limited surgical procedure if they meet certain criteria.