Intraoperative lymphatic mapping and sentinel lymph node biopsy using radioactive tracer in gastric cancer

Gastric cancer continues to be a significant health problem around the world. Surgical resection with a lymph node dissection remains the only potentially curative treatment with gastric cancer. Determination of the extent of lymph node dissection required on the basis of actual node involvement in patients with gastric cancer is important as less extensive dissection may reduce postoperative morbidity and mortality rates. The current study examines the feasibility and reliability of sentinel lymph node biopsy in gastric cancer.

A total of 32 patients who underwent gastrectomy with extended lymphadenectomy were enrolled in this study. A total volume of 148 MBq (2 mL) technetium-99m-radiolabeled, filtered sulphur colloid solution was injected into the primary lesion under gastroscopy 2 hours before the operation. Lymph nodes were examined as soon as possible by a hand-held gamma probe during the operation, without significant manipulation of the stomach or greater omentum. A sentinel lymph node (SLN) was defined by a level of radioactivity 10 times higher than the background.

Thirty-one of 32 patients had successful SLN biopsy, with a success rate of 97%. The sensitivity, specificity, positive predictive value, and negative predictive value of SLN biopsy were 100%, 95%, 90%, and 100%, respectively.

SLN biopsy using gamma probe in gastric cancer is a feasible procedure with high sensitivity and accuracy. This technique may be of a great benefit to surgeons in planning the extend of lymph node dissection in gastric cancer.