Lymphatic drainage patterns in oral squamous cell carcinoma: findings of the ACOSOG Z0360 (Alliance) study

Objective: The purpose of our study was to correlate sentinel lymph nodes (SLN) found on planar lymphoscintigraphy (LS) to SLN found with gamma probe-directed sentinel lymph node biopsy (SLNB) for T1/T2 N0 oral cavity cancer.

Study design: Prospective cooperative group trial.

Setting: Academic medical centers.

Subjects and methods: One hundred forty adults with untreated T1/T2 N0 squamous cell carcinoma (SCC) of the oral cavity underwent planar LS, resection, SLNB, and neck dissection. Location of SLN by planar LS and SLNB and of metastases were compared to each other and historical data of regional metastases.

Results: SLNs located by planar LS and SLNB were predominantly in levels I through IV. There was heterogeneity in the number of SLNs found at planar LS and at SLNB, which was significantly different in levels II and III (P < .0001). In 14 of 33 cases with bilateral drainage on planar LS, SLNB detected only unilateral SLN. Sensitivity of planar LS in predicting the level of SLN was 41% to 63%, and specificity was 68% to 95%. Comparison of locations of the metastases to historical data showed fewer metastases to level I in our study (P = .03). Metastases occurred predominantly in levels I through III. In 1 case of a lateral tongue cancer, a contralateral SLN was the only positive node.

Conclusion: Lymphatic drainage patterns and metastases involved predominantly levels I through III. Planar LS is not sensitive for predicting the levels of SLN, and in levels II and III, the rate of detection of SLN between the 2 modalities is significantly different.