Relationship Between Pharyngeal Residues Assessed by Bolus Residue Scale or Normalized Residue Ratio SCALE and Risk of Aspiration in Head and Neck Cancer Who Underwent Videofluoroscopy

Dysphagia affects 60–75% of patients treated for head and neck cancer (HNC). We aimed to evaluate the association between residue severity and airway invasion severity using a videofluoroscopic swallowing study and identify risk factors for poor penetration–aspiration outcomes in patients with dysphagia treated for HNC. Penetration–Aspiration Scale (PAS) was used to assess airway invasion severity, while residue severity was assessed using both the Bolus Residue Scale (BRS) for residue location and the Normalized Residue Ratio Scale (NRRS) for residue amount. Relevant covariates were adjusted in the logistic regression models to account for potential confounding. Significantly higher abnormal PAS was reported for increased piriform sinus NRRS (NRRSp) [odds ratio (OR), 4.81; p = 0.042] with liquid swallowing and increased BRS value (OR, 1.52; p = 0.014) for semi-liquid swallowing in multivariate analysis. Tumor location, older age, and poorer Functional Oral Intake Scale (FOIS) were significant factors for abnormal PAS in both texture swallowings. After adjusting for confounding factors (sex, age, and FOIS score), NRRS model in liquid swallowing (area under the curve [AUC], 0.83; standard error = 0.04, 95% confidence interval [CI]: 0.75, 0.91) and BRS in semi-liquid swallowing (AUC, 0.83; SE = 0.04; 95% CI: 0.76, 0.91) predicted abnormal PAS. The results indicate that while assessing residue and swallowing aspiration in patients with HNC, it is important to consider age, tumor location, and functional swallowing status. The good predictability of abnormal PAS with BRS and NRRS indicated that residue location and amount were both related to the aspiration event in patients with HNC.