Comparison of different tracer methods in detecting sentinel lymph nodes in gastric cancer

Abstract

Objective To explore the optimum sentinel lymph node (SLN) mapping method in gastric cancer. Methods The clinical data of 59 patients who were confirmed with gastric cancer at Guangzhou General Hospital of Guangzhou Military Command from January 2004 to August 2008 were retrospectively analysed. Patent blue V dye was used in 20 patients (group A), technetium-99m sulfur colloid was used in 20 patients (group B),and a combination of patent blue V dye and technetium-99m sulfur colloid were used in 19 patients (group C).The number of SLNs detected, and accuracy and false-negative rate of SLNs in diagnosing regional lymph node metastasis were analysed by t test and chi-square test. Results The numbers of SLNs detected in groups A, B and C were 38 (1.9 per case), 31 (1.6 per case) and 56 (2.9 per case), respectively. In group C, 46 SLNs were screened out by patent blue V dye and technetium-99m sulfur colloid simultaneously, six SLNs were only detected by patent blue V dye and four only by technetium-99m sulfur colloid. There was a significant difference in the number of SLNs detected among the three groups (t = 4.35, P ＜ 0. 05 ). The number of SLNs detected in group C was significantly greater than that in groups A and B (t = 4. 21, 3. 54, P ＜ 0.05 ). The accuracy and false-negative rate of SLNs in diagnosing regional lymph node metastasis were 95% (19/20) and 5% (1/20) in group A, 90% (18/20) and 10% (2/20) in group B, and 100% (19/19) and 0 in group C. The accuracy was significantly higher (x2 = 163.01, P ＜ 0.05) and the false-negative rate was significantly lower in group C compared with those in groups A and B (x2 = 170. 14, P ＜ 0. 05). Conclusion A combination of dye and radioactive tracer is a favorable method for detecting SLNs in gastric cancer. Key words: Gastric neoplasms; Sentinel lymph nodes; Tracer methods; Dye; Nuclide