| Summary: | Abstract Objective To investigate the frequency, distribution, and potential factors of lymphatic metastasis at each nodal level, and stratify the risk of lymph node metastasis in hypopharyngeal squamous cell carcinoma based on computed tomography. Methods Contrast‐enhanced computed tomography images of 176 patients with pathologically confirmed hypopharyngeal squamous cell carcinoma without any cancer‐related therapeutic history were analyzed retrospectively. The lymphatic metastasis ratio at each nodal level was determined. Potential factors that correlated with lymph node metastasis were identified using univariate and multivariate analyses. Results Metastatic lymph nodes were found in 145 (82.4%) of 176 patients. The lymphatic metastasis ratio was 0.6% (Ia), 4.0% (Ib), 67.6% (IIa), 43.8% (IIb), 45.5% (III), 13.1% (IV), 5.1% (Va), 1.7% (Vb), 1.7% (VIa), 12.5% (VIb), and 15.9% (VII) for each nodal level in the ipsilateral neck. In contrast, a lower lymphatic metastasis ratio was observed in the contralateral neck, with the highest measuring 18.2% at level IIa. Esophageal invasion was highly correlated with an increased risk of developing level VIb metastasis (P = 0.019). Furthermore, posterior pharyngeal wall invasion was highly correlated with an increased risk of level VII metastasis (P = 0.014). Conclusion In general, nodal levels IIa, III, and IIb were highly susceptible to metastasis in the ipsilateral neck. Nodal levels IV, VIb, and VII in the ipsilateral neck, and IIa in the contralateral neck showed a moderate risk of metastasis. Levels I and V were considered low risk. The anatomical characteristics and infiltration of tumors in different subsites should also be considered in the delineation of the clinical target volume.
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