ABSTRACT
The objective of the study was to evaluate the association between changes in laryngeal sensation and initiation of swallowing reflex or swallowing function before and after (chemo)radiotherapy. A prospective study was conducted in a tertiary referral university hospital. Thirteen patients who received (chemo)radiotherapy for treatment of laryngeal or hypopharyngeal cancer were included. Laryngeal sensation was evaluated at the tip of the epiglottis before and 1, 3 months, and 1 year after (chemo)radiotherapy. Videofluoroscopy was performed at the same time. Quantitative determinations included changes in laryngeal sensation, computed analysis of pharyngeal delay time, the distance and velocity of hyoid bone movement during the phase of hyoid excursion, and pharyngeal residue rate (the proportion of the bolus that was left as residue in the pharynx at the first swallow). Laryngeal sensation significantly deteriorated 1 month after (chemo)radiotherapy, but there was a tendency to return to pretreatment levels 1 year after treatment. Neither pharyngeal delay time nor displacement of the hyoid bone changed significantly before and after (chemo)radiotherapy. In addition, there was no significant difference in the mean velocity of hyoid bone movement and the amount of stasis in the pharynx at the first swallow before and after (chemo)radiotherapy. After (chemo)radiotherapy, laryngeal sensation deteriorated. But, in this study, videofluoroscopy showed that swallowing reflex and function were maintained.
Subject(s)
Carcinoma, Squamous Cell/drug therapy , Carcinoma, Squamous Cell/radiotherapy , Head and Neck Neoplasms/drug therapy , Head and Neck Neoplasms/radiotherapy , Laryngeal Nerves/physiopathology , Larynx/physiopathology , Pharynx/innervation , Sensation/radiation effects , Aged , Aged, 80 and over , Chemoradiotherapy , Deglutition , Female , Follow-Up Studies , Humans , Laryngeal Nerves/drug effects , Laryngeal Nerves/radiation effects , Larynx/drug effects , Larynx/radiation effects , Male , Middle Aged , Pharynx/physiopathology , Pharynx/radiation effects , Prospective Studies , Squamous Cell Carcinoma of Head and Neck , Time FactorsABSTRACT
Radiotherapy of the laryngopharynx sometimes leads to functional disabilities including swallowing dysfunction. One of the reasons for these disabilities is a deterioration of laryngeal sensation. Laryngeal sensation is an important factor in swallowing, but quantitative evaluation of laryngeal sensation has been difficult. In this study, we evaluated changes in laryngeal sensation before and after radiotherapy for laryngeal and hypopharyngeal cancer, using a flexible laryngoscope and probes. This study was conducted in 12 patients, 8 with laryngeal cancer and 4 with hypopharyngeal cancer, who received radiotherapy alone or chemoradiotherapy at our medical centre. Measurements were performed using a 3.3-mm-diameter flexible laryngoscope with a probe port and four types of probes with 0.06-, 0.13-, 0.20-, and 0.30-mm nylon filaments attached to a wire tip. Sensation was evaluated at the tip of the epiglottis and the arytenoid region. Measurements were performed before radiotherapy, 1, 3 months, and 1 year after completion of radiotherapy. Sensation of the epiglottis and arytenoid deteriorated significantly 1 and 3 months after radiotherapy compared with before radiotherapy. Laryngeal sensation recovered in most cases within 1 year after radiotherapy. The present study clearly demonstrates the deterioration of laryngeal sensation with radiotherapy.
