Objective assessment of swallowing dysfunction and aspiration after radiation concurrent with chemotherapy for head-and-neck cancer.

PURPOSE: To objectively assess swallowing function after an intensive chemoradiation regimen for locally advanced head-and-neck cancer and to assess the clinical implications of swallowing dysfunction. PATIENTS AND METHODS: Twenty-nine patients with nonresectable Stage IV head-and-neck cancer participated in a Phase I study of radiation, 70 Gy/7 weeks, concurrent with weekly gemcitabine. Because of a high rate of mucosal toxicity, reduced drug doses were delivered to subsequent patient groups: 300, 150, 50, and 10 mg/m(2)/week. Twenty-six of these patients underwent prospective evaluation of swallowing function with videofluoroscopy and esophagogram. Studies were performed pretherapy, early post-therapy (1-3 months), and late post-therapy (6-12 months).
RESULTS: Complete tests were performed pretherapy in 22 patients, early post-therapy in 20, and late post-therapy in 13. Twenty-five patients had at least one post-therapy study. Post-therapy dysfunction was characterized by reduced inversion of the epiglottis, delayed swallow initiation and uncoordinated timing of the propulsion of the bolus, opening of the cricopharyngeal muscle, and closure of the larynx, all of which promoted aspiration during and after the swallow. In addition, reduced base-of-tongue retraction with reduced contact to the posterior pharyngeal wall and incomplete cricopharyngeal relaxation resulted in pooling in the pyriform sinuses and vallecula of residue, which was frequently aspirated after the swallow. Post-therapy aspirations were typically "silent," eliciting no cough reflex, or the cough was delayed and noneffective in expelling the residue. Aspiration was observed in 3 patients (14%) in the pretherapy studies, in 13 (65%) in the early post-therapy studies, and in 8 (62%) in the late post-therapy studies (aspiration rates post-therapy vs. pretherapy: p = 0.0002). Six patients had pneumonia requiring hospitalization 1-14 months after therapy (median: 2.5 months), being the likely cause of death in 2 patients. Five cases of pneumonia occurred among 17 patients who had demonstrated aspiration in the post-therapy studies, compared with no cases of pneumonia among 8 patients who had not demonstrated aspiration (p = 0.1). Of the 4 patients who had not undergone any post-therapy study, 1 developed pneumonia. Mucositis scores, prolonged tube feeding, presence of tracheostomy tube, and gemcitabine doses were not found to be related to aspiration or pneumonia risk.
CONCLUSIONS: After intensive chemoradiotherapy, significant objective swallowing dysfunction is prevalent. It promotes aspiration, which may not elicit a cough reflex and may be associated with pneumonia. Aspiration pneumonia may be an underdocumented complication of chemoradiotherapy for head-and-neck cancer. Future studies should examine whether routine post-therapy videofluoroscopy and training aspirating patients in safe swallowing strategies can reduce this risk.