Results of fiberoptic endoscopic evaluation of swallowing vs. radiation dose in the swallowing muscles after radiotherapy of cancer in the oropharynx

Background and purposeDysphagia is a serious complaint but frequently underreported. This paper assesses for oropharyngeal cancer (OPC) the relationship between the dose received by the swallowing structures, and the findings of a fiberoptic endoscopic evaluation of the swallowing process (FEES).Materials and methodsBetween 2000 and 2005, 60 of 67 OPC patients local-regionally NED for at least one year following treatment responded to three types of QoL questionnaires; i.e. Performance Status Scales, EORTC H&N35, and M.D. Anderson Dysphagia Inventory. Twenty-four patients agreed to the FEES procedure. The main swallowing muscles were delineated, with the mean dose per muscle calculated using the original 3D CT-based treatment plans. Regression analysis was performed between FEES variables and the doses in the different swallowing muscles and the dysphagia related questionnaires.ResultsA significant relationship was found between the results of FEES and the mean dose in the superior constrictor muscle (SCM). Some of the subjective dysphagia complaints were significantly correlated with the FEES variables in this retrospectively study.ConclusionA higher dose in the SCM generally results in worsening of the findings obtained by the FEES examination.