Laparoscopic Lymphatic Mapping and Sentinel Node Biopsies for Early‐stage Gastric Cancer: The Cause of False Negativity

Abstract

Sentinel node (SN) biopsies might be useful for performing minimally invasive surgery without interrupting surgical curability. This study examined the cause of false negativity during laparoscopic lymphatic mapping and SN biopsies for early-stage gastric cancer. Thirty-seven patients with gastric cancer (preoperative stage T1-2 or N0) who underwent laparoscopic lymph node mapping and SN biopsies between March 2001 and June 2004 were enrolled in this study. The tracer, patent blue and technecium-99m-labeled tin colloid, was injected endoscopically. Blue-stained or radioactive nodes were defined as SNs. Gastrectomy with lymphadenectomy was performed then the results of the SN biopsies were compared with the final diagnosis of the removed lymph nodes in permanent sections. Sentinel nodes were successfully identified in 35 patients (94.6%), and they were positive in 3 of 4 patients with metastatic lymph nodes; sensitivity was 75% and specificity was 100%. Sentinel node status could therefore be used to diagnose lymph node status with 97.1% accuracy. Of 6 SNs with metastasis, 5 showed radioactivity, and only 2 were blue stained. In the false negative case, a radioactive SN with metastasis in the right paracardial region was missed during laparoscopic mapping. An error in laparoscopic intracorporeal detection of the radioactive node with metastasis occurred because we could not eliminate the shine-through effect. We found that during laparoscopic SN mapping there is a high risk of false negativity with SNs located in the right paracardial region. To apply laparoscopic SN mapping to early-stage gastric cancer patients, the shine-through effect must be eliminated because radiotracers are essential for this method.

Factors associated with detection failure and false‐negative sentinel node biopsy findings in gastric cancer: Results of prospective single center trials

“…This finding implies the lymphatic system of the stomach is diverse and multidirectional and that skip metastasis frequently occurs [9,10]. Tonouchi et al [26] conducted a literature review to determines the cause of SNB false-negativity in gastric cancer, and concluded that the most common cause was lymphatic occlusion due to massive lymph node metastasis; other identified causes were injection failure, pathologic failure, and intraoperative misses. In the second trial of the present study, clinicopathologically T2 tumors larger than 4 cm tended to be false-negatives, which suggests lymph node metastasis occurs in an unpredictable directional manner, and the possibility of lymphatic obstruction [18].…”

Feasibility of laparoscopic sentinel basin dissection for limited resection in early gastric cancer

“…Tonouchi et al reported a false-negative case with a metastatic lymph node in the right paracardial area (Station 1), which was in the same lymphatic basin as an SN [22]. They found that the radioactive metastatic lymph node had been missed due to the shinethrough effect.…”

“…The necessity of SB dissection is demonstrated by recent publications, especially those concerning laparoscopic SN biopsy in EGC [22][23][24]. Tonouchi et al reported a false-negative case with a metastatic lymph node in the right paracardial area (Station 1), which was in the same lymphatic basin as an SN [22].…”

Evaluation of the novel near-infrared fluorescence tracers pullulan polymer nanogel and indocyanine green/γ-glutamic acid complex for sentinel lymph node navigation surgery in large animal models

“…The most commonly used tracers for sentinel node mapping are vital dyes, which are detected by visual inspection, and radioisotopes conjugated with colloid particles, which are detected by gamma probes yielding audible signals [4][5][6][7]. In gastric cancer, low sensitivity and rapid dispersion of vital dyes, as well as the need for strict radiohazard-proof protocols and the invisibility of radioisotopes, have been recognized as limitations [8].…”