The Relationship between Swallowing Muscle Mass and Tongue Muscle Strength and Endurance in Head and Neck Cancer Patients.

Sarcopenic dysphagia is a significant concern in head and neck cancer (HNC) patients and contributes to malnutrition, aspiration pneumonia and poor clinical outcomes. Although tongue strength (TS) and swallowing muscle mass (SwMM) are central components of swallowing physiology, their relationship in HNC patients remains unclear. This study investigated the association between SwMM and TS and tongue endurance in HNC patients. This prospective cross-sectional study was conducted at the University Medical Center Groningen between February 2023 and April 2025. Fifty-three patients with primary mucosal HNC were included before treatment. SwMM was quantified on contrast-enhanced CT scans using the mid-sagittal tongue complex muscle (TCM) area as a proxy for SwMM volume. TS and tongue endurance were measured with the Iowa Oral Performance Instrument. Associations were evaluated using Pearson and Spearman correlation analyses and univariable and multivariable linear regression adjusted for age, sex, and nutritional status. SwMM was not significantly correlated with maximum TS at the anterior or posterior positions (r = 0.080 and r = 0.048, respectively; both p > 0.05), nor with tongue endurance (r= - 0.043 and r= - 0.004, respectively; both p > 0.05). Regression analyses confirmed that SwMM was not significantly associated with tongue performance, including in adjusted multivariable models. SwMM and tongue muscle performance represent distinct physiological domains in untreated HNC patients. The mid-sagittal TCM area, as a proxy for SwMM, was not associated with tongue pressure capacity, suggesting that TS alone may overlook lower SwMM. CT-based SwMM assessment is feasible but should complement functional assessments for a comprehensive evaluation of sarcopenic dysphagia.