Timing of swallowing events after single-modality treatment of head and neck carcinomas with radiotherapy.

This paper reports the results of a preliminary study designed to evaluate swallowing function in 20 patients 1 year after successful treatment of head and neck carcinomas with radiotherapy. The timing of swallowing events was evaluated by videofluoroscopy. The mean values for each measure were compared to the normative data from 60 control subjects. The radiotherapy patients demonstrated prolonged pharyngeal bolus transit and a delay of laryngeal closure. Hyoid bone elevation began late relative to the onset of bolus movement. A strong trend toward a delay in hyoid elevation relative to bolus movement was demonstrated. The time required for the hyoid bone to reach maximal elevation did not differ from that in normals, but the hyoid was held in an elevated position for a longer period of time. As a result of changes in hyoid movement, the upper esophageal sphincter tended to open early relative to the arrival of the bolus. In conclusion, changes in deglutition occur after radiotherapy, presumably as an adaptation to changes in tissue compliance.