Usefulness of radiologic examinations for diagnosing level VI lymph node metastasis in patients with laryngohypopharyngeal carcinoma

The aim of this study was to estimate the usefulness of imaging modalities for diagnosing level VI lymph node metastasis in patients with laryngohypopharyngeal cancer. A retrospective review of 138 patients with squamous cell carcinoma of the larynx or hypopharynx who underwent central compartment neck dissection (CCND) was performed. Level VI metastasis occurred in 29 of 138 (21 %) patients. CT accuracy and sensitivity for level VI lymph node was 85.5 and 48.3 %, respectively. Respective values for MRI, US, and PET were 84.4 and 41.4 %, 87.7 and 44.8 %, and 81.2 and 34.5 %. CT combined with US demonstrated the best result in sensitivity (51.7 %) and negative predictive value (NPV) (88.1 %) compared to those of other imaging techniques. CT combined with US could improve sensitivity and NPV compared to CT or US alone. Considering cost-effectiveness and the highest results in all parameters compared to those of other combinations of imaging techniques, CT combined with US could be the best preoperative imaging modalities for evaluating laryngohypopharyngeal cancer. However, these imaging techniques are not absolutely reliable methods for detecting occult metastasis in the level VI due to high false-negative rates. Elective CCND should be considered in indicated patients (>N2b, T4), even if physical examinations and the radiologic findings of level VI nodes are negative.