The relationship between muscle fibrosis and the hyoid displacement in dysphagic patients with nasopharyngeal carcinoma after radiation therapy / 中华物理医学与康复杂志

ABSTRACT

Objective To evaluate the relationship between muscle fibrosis and the displacement of the hyoid bone while swallowing among patients with nasopharyngeal carcinoma (NPC) after radiation therapy.Methods Twenty-six NPC patients with dysphagia were recruited.Shear wave elastography was performed to assess the fibrosis of the mylohyoid muscle.The horizontal and vertical displacement of the hyoid bone were measured based on the videofluoroscopic swallowing study,and the severity of dysphagia was determined using the penetration-aspiration scale (PAS).The correlation between the modulus value of the mylohyoid muscle and the horizontal and vertical displacement of the hyoid bone were analyzed,respectively.Receiver-operating characteristic (ROC) curve were constructed to assess the diagnostic ability of modulus value for the severity of dysphagia above grade 5 of PAS.Results For patients whose PAS was higher than grade 5,the modulus value of mylohyoid muscle was negatively correlated with the displacement of hyoid bone,while such correlation was absent for patients whose PAS grading were less than or equal to 5.Sensitivity and specificity by modulus value to detect dysphagia were 80％ and 81.8％,respectively,with the best cut-off value of 14.37 kPa.Conclusion The reduction of hyoid bone displacement can be partially attributed to muscle fibrosis for post-radiation NPC patients with severe dysphagia.The modulus value measured by Shear wave elastography could be used as a supplementary way to monitor the development of dysphagia.