[Application of carbon nanoparticles as lymph node tracers in patients with cN0 lingual squamous cell carcinoma un-dergoing neck dissection].

OBJECTIVE: This study aimed to investigate the value of carbon nanoparticles as lymph node tracers in neck dissection for cN0 lingual squamous cell carcinoma patients.

METHODS: Ninety-six patients with cN0 lingual squamous cell carcinoma were recruited to undergo surgical treatment were randomly divided into two groups, namely, the carbon nanoparticle-labeled group (the experimental group, 50 cases) and the control group (46 cases). Carbon nanoparticle suspension was injected into the submucosal layer around the site of the primary tumor at three or four points (0.1 mL for each point) 12 h before surgery. Supraomohyoid neck dissection (SOHND, Levels Ⅰ to Ⅲ) or comprehensive neck dissection (CND, Levels Ⅰto Ⅴ) were performed based on the size and location of the primary tumor. All the lymph nodes were dissected and separated from the ex vivo surgical specimens for histopathological evaluation. The number, size, location, and pathological result of all the lymph nodes were compared between the two groups. Statistical analyses were conducted by SPSS 19.0 software.

RESULTS: A total of 1 137 lymph nodes were detected in 31 SOHND patients. The average number of lymph nodes detected in the experimental group was (43.79±19.23) /case, which was significantly higher than that in the control group [(30.82±8.77) /case] (P=0.019). Level Ⅲ covered the largest number of lymph nodes in the two groups. However, the number and proportion of lymph nodes found in Level Ⅱ of the experimental group were significantly higher than those of the control group (P=0.000). A total of 3 938 lymph nodes were detected in 65 CND patients. The average number of lymph nodes detected in the experimental group [(66.67±20.02) /case] was larger than that in the control group [(53.03±20.98) /case] (P=0.026). The difference in the lymph node location between the two groups was not statistically significant (P=0.354). In the two neck dissection methods, both the proportion of minute lymph nodes and the accuracy of the detected lymph nodes in the experimental group were significantly larger than those in the control groups (P=0.000). Compared with the control group, more metastases were proven by the carbon nanoparticle-labeled lymph nodes (P=0.000) in the experimental group.

CONCLUSIONS: Carbon nanoparticles as lymph node tracers in patients with cN0 lingual squamous cell carcinoma undergoing neck dissection can increase the number of detected lymph nodes, especially the minute nodes. Such nanoparticles can further ensure the thoroughness of neck dissection and the accuracy of clinicopathological stage.