[Sentinel lymph node radiolocalization in squamous cell carcinoma of the oral tongue]

At present, there is no clinical examination that can accurately assess the lymph node metastasis status of oral tongue carcinoma with clinically negative neck lymph node (cN0) before operation. Therefore, the treatment of cN0 neck is still controversial. Sentinel lymph node (SLN) biopsy may be the evidence for individual treatment of cN0 neck. This study was to explore the feasibility of SLN radiolocalization, and to investigate the clinical value of SLN detection in squamous cell carcinoma of the oral tongue.

Twenty-one oral tongue squamous cell carcinoma patients with cN0 necks were recruited, among which 1 had received primary dissection before. 99mTc-SC, as the tracer, was injected into the submucosa around primary tumor before operation. Lymphoscintigraphy was performed immediately in 5 cases. The gamma probe was used to identify SLNs for all cases before and during operation. All patients received supraomohyoid neck lymph node dissection. The pathologic results were considered as golden standard to evaluate the effectiveness of SLN radiolocalization. SLNs that had been reported as negative by routine pathologic examination were examined by immunohistochemistry.

The detection rate of SLNs was 100%. Among the 21 patients, the pathologic results of SLNs for 21 patients accorded with the pathologic results of neck lymph node dissection; the accuracy rate was 95%. In 1 patient, the pathologic result of SLNs was negative, but that of neck lymph node dissection was positive. Micrometastases were found in 3 of 41 detected lymph nodes by immunohistochemstry.

SLN radiolocalization in squamous cell carcinoma of the oral tongue is feasible. SLN biopsy can well predict the cervical lymph node metastasis status of oral tongue carcinoma, but further investigation is necessary to determine its clinical value.