Sentinel Lymph Node Biopsy for Locally Recurrent Oral Squamous Cell Carcinoma with a Previously Treated Neck

BackgroundNeck management in recurrent cN0 oral squamous cell carcinoma (SCC) remains controversial. We aimed to elucidate the utilization of sentinel lymph node (SLN) biopsy in recurrent oral SCC.MethodsPatients with locally recurrent cN0 oral SCC who underwent SLN biopsy were retrospectively analyzed. The primary outcome variable was the diagnostic accuracy of SLN biopsy, alongside an examination of aberrant drainage in relation to previous neck interventions, wherein aberrant drainage was defined as SLNs situated outside ipsilateral levels I-III or in the contralateral neck.ResultsA total of 169 patients were included, achieving an SLN detection rate of 100%. SLN biopsy confirmed nodal metastasis in 29 patients, but failed to identify 9 cases, leading to a false negative rate (FNR) of 23.7% and a negative predictive value (NPV) of 93.6%. The efficacy of the biopsy was influenced by prior neck management, with the elective neck dissection (END) + radiotherapy cohort exhibiting the highest FNR of 26.1% and the lowest NPV of 90.0%. Aberrant lymphatic drainage was documented in 54 patients, with 30 cases demonstrating ipsilateral drainage and 14 cases revealing contralateral drainage. The END group recorded the highest number of SLNs detected, while the END + radiotherapy group displayed the greatest propensity for aberrant lymphatic drainage and non-SLN metastasis.ConclusionsIn patients with locally recurrent oral SCC, SLN biopsy showcased a commendable capacity to show aberrant lymphatic drainage and detect occult metastases, although false negative results were prevalent among individuals previously treated with END and radiotherapy.