Lymphatic Mapping Patterns in Early Oral Squamous Cell Carcinoma

Abstract

Objectives:

Correlate location of sentinel nodes on lymphoscintigraphy versus sentinel lymph node biopsy (SLNB) and lymphatic metastases for T1 and T2 N0 oral cavity cancer.

Methods:

This was a prospective cooperative group trial of 140 patients with untreated T1 and T2 N0 oral cancers at academic medical centers. Interventions were lymphoscintigraphy, resection of the primary, SLNB, and immediate neck dissection. The outcome measures were location of sentinel nodes by lymphoscintigraphy versus SLNB, and location of metastases.

Results:

Lymph nodes located by lymphoscintigraphy and SLNB were found predominately in levels I through IV. There was heterogeneity in the number of the lymph nodes found at lymphoscintigraphy and at SLNB, which was significantly different in levels II and III (P < 0.0001). In 6 of 28 cases with bilateral drainage on imaging, SLNB detected only unilateral sentinel nodes. Sensitivity of lymphoscintigraphy in predicting the levels of sentinel nodes ranged from 42% to 63%, and specificity from 71% to 95%, for each level. Comparison of locations of nodal metastases to historical data showed fewer metastases to level I in our study (P = 0.0295). Metastases occurred predominantly in levels I, II, and III. In one case of a lateral tongue cancer, a contralateral node was the only positive node.

Conclusions:

Lymphatic drainage patterns and lymph node metastases involved predominantly levels I, II, and III. Lymphoscintigraphy is not very sensitive for predicting the levels of sentinel nodes. In levels II and III, the rate of detection of lymph nodes between the two modalities is significantly different.