Dose-effect relationships between swallowing structures and long-term dysphagia in post intensity-modulated radiotherapy nasopharyngeal cancer survivors : a case-series

Abstract

This study was a case series for dose-effect relationships between dysphagia/aspiration-related structures (DARS) and chronic dysphagia in post intensity-modulated radiotherapy (IMRT) of nasopharyngeal cancer (NPC) survivors. Three participants were recruited for analysis. The four DARS identified were glottis and supraglottic larynx (GSL), parotid glands, anterior oral cavity and tongue base. The swallowing outcome measurements used were Functional Oral Intake Scale, patient self-reported dysphagia-specific questionnaires M. D. Anderson Dysphagia Inventory and Head-and-Neck cancer Survivors Assessment of Mealtimes, instrumental Fiberoptic Endoscopic Evaluation of Swallowing Examination and clinician-directed bedside swallowing examination. The results support present literatures of the head and neck cancer survivors, and is suggestive that higher dose to the DARS would induce higher risk of chronic dysphagia in NPC survivors.