removed. Once removed, the node is probed away from the patient and then the counts are compared to the wound bed. If there is a significant drop after the node is excised, then it is sent to pathology for fine cut frozen section. All other nodes that have counts of 10% or more of the original node are also removed. Depending on the site of the primary, a lead malleable may be useful in shielding the tracer counts from floor of mouth tumors and nodes in level I. Sometimes it is useful to excise the primary tumor to remove any interfering signals. Overall, sentinel nodes are able to be located in more than 90% of cases but this success is highly user dependent. A European survey found that surgeons with less than ten cases only had a 56% success rate in finding sentinel nodes. When sentinel nodes are located, there are usually 2-3 nodes present and occult malignancy has been reported to be as high as 46%. Overall there is about a 10% false negative rate which was associated with larger primary tumors (T3) and could be due to gross nodal involvement rather than microscopic tumor metastases.
Complications for SLNB are reported to be less than one percent. All of the complications have been reported in cutaneous malignancy primaries. Almost all complications are related to limited incisions and subsequent facial nerve damage.
Trials are ongoing to evaluate the efficacy of sentinel node biopsy in N0 oral SCCA when compared to watchful waiting or elective treatment of the neck with surgery or radiation.
Ferlito, A et al. Neck Dissection: past, present and future? J. Laryngol Otol. 2005 (1) 1-6.
Civantos, F, Moffat, F, Goodwin, W. Lymphatic Mapping and Sentinel Lymphadenectomy for 106 Head and Neck Lesions: Contrasts Between Oral Cavity and Cutaneous Malignancy Laryngoscope, 116 (Suppl. 109):1–15, 2006
Oral Cancer: Correlation of Sentinel Lymph Node Biopsy and Selective Neck Dissection Histopathology
Tschopp, L, Nuyens, M, Stauffer, E, Krause, T, Zbaren, P. The value of frozen section analysis of the sentinel lymph node in clinically N0 squamous cell carcinoma of the oral cavity and oropharynx Bern, Switzerland Otolaryngol Head Neck Surg 2005;132:99-102.
Hydea, E. Prvulovichb, L. Newmanc, W.A. Waddingtonb, D. Visvikisb, P. Ellb. A new approach to pre-treatment assessment of the N0 neck in oral squamous cell carcinoma: the role of sentinel node biopsy and positron emission tomography Oral Oncology 39
Shoaib, T. The Accuracy of Head and Neck Carcinoma Sentinel Lymph Node Biopsy in the Clinically N0 Neck CANCER June 1, 2001 / Volume 91 / Number 11