gms | German Medical Science

The sentinel node is the first lymph node to receive drainage from the primary tumor. In order to detect the sentinel node, there are various kinds of tracers (radiolabeled particles and vital dyes). The prediction of node status in breast cancer or malignant melanoma has been reported to exceed 95 %. However, it is not clear whether sentinel node navigation surgery is applicable to gastric cancer surgery or not. We investigated the feasibility of sentinel node staining and its accuracy in predicting the lymph node status in patients with gastric cancer.

Patients consisted of 38 gastric cancer cases (31 male, 7 female, 60.4 + 8.8 years old) who underwent curative surgery from April 2001 to August 2003 at Japan Railway Tokyo General Hospital. In all patients, the absence of cancer invasion to the serosal layer of the stomach was macroscopically confirmed (T1 (n =31) or T2 (n = 7)). After laparotomy, a fine needle (26-gauge) was inserted into the subserosal layer around the primary tumor and indocyanine green (ICG) was injected. Total amount of injected ICG was 25 mg (5 ml) for each patient. Sentinel nodes (SN) were defined as lymph nodes those were stained green within 5 minutes after ICG injection and were removed before distal gastrectomy (n = 32) or total gastrectomy (n = 6) with extended lymph node dissection (D2 procedure according to the Japanese classification of gastric carcinoma). Stained nodes, unstained nodes (non-SN), and resected stomach were fixed in 20 % formalin and embedded in paraffin, and 5-micrometer sections were cut to be stained with hematoxylin and eosin for histologic examination. We compared the location and numbers of SN and histological diagnosis of SN and non-SN.

In all patients, SNs were detected without any complication. The number of SN was 3.3 + 2.2 and that of non-SN was 19.6 + 8.6. Out of 38 cases, 29 patients had no SN metastases and 9 had metastases in SN. The 29 cases without metastases in SN had no metastases in non-SN. Among 9 cases with metastases in SN, 6 patients revealed metastases in both of SN and non-SN, and three revealed metastases only in SN and no metastases in non-SN. There was no patient who had metastases only in non-SN. Both of sensitivity and specificity was 100 %.

SN staining by use of ICG can be performed with 100 % success rate. SN status can predict the lymph node status accurately in patients with T1 and T2 gastric cancer. When you find no metastases in SN in T1 or T2 gastric cancer patients, you can perform partial resection of stomach with more limited lymph node dissection.