[Evaluation of sentinel lymph node in squamous cell carcinoma of the head and neck].
ABSTRACT To assess the feasibility of sentinel lymph node (SLN) radiolocalization in stage in head and neck squamous cell carcinoma and to gain insight as to whether the sentinel lymph node could be prognostic of regional micrometastatic disease.
A prospective trial was made on the application sentinel lymph node radiolocalization in 10 patients with NO squamous cell carcinoma of the head and neck region. For each patient a peritumoral submucosal injection of filtered technetium 99m prepared with dextran colloid (99mTc-DX) was performed immediately. After 30 minutes, focal areas of accumulation corresponding to sentinel lymph nodes (SLN) were marked on the skin surface. The SLN was localized by lymphoscintigraphy and intraoperatively through the intact skin by a hand-held gamma-probe. SLN was defined as the count of lymph node could be detected 4 times more than that of background. Complete neck dissections were performed, and SLNs were identified for later histological evaluation and comparison to the remaining lymphadenectomy specimen.
SLN radiolocalization accurately identified one or more SLNs in the ten cases. 3 of 10 cases revealed occult metastatic disease. Therefore the negative metastasis rate was 30% (3/10). The positive rate of SLN and nonsentinel lymph node (NSLN) were 22.7% (5/22) and 0.4% (1/247) respectively. Serial sectioning (SS) and immunohistochemical (IHC) on SLNs would reduce the false-negative rate of sentinel lymph node biopsy (SLNB). There was no instance in which SLN was negative for micrometastatic disease while being positive in a nonsentinel lymph node.
SLN evaluation in NO neck in squamous cell carcinoma of the head and neck is accurately feasible and seems to adequately predict the presence of occult metastasis. Although SLN radiolocalization in head and neck squamous cell carcinoma may potentially reduce the time, cost, and morbidity of regional lymph node management, more experience with technique is required before its role can be determined.