Silent aspiration and swallowing physiology after radiotherapy in patients with nasopharyngeal carcinoma

Background. There is a paucity of knowledge on dysphagia in patients with nasopharyngeal carcinoma postradiotherapy (NPC post-RT). The purpose of this study was to establish silent aspiration occurrence, safe bolus consistency, and their relationship with swallowing physiology in patients with dysphagic NPC post-RT. Methods. Eighty-five patients with dysphagic NPC post-RT were assessed across 4 bolus consistencies. We compared penetration-aspiration scores against 4 swallowing physiology impairments. Results. Silent aspiration occurred in 65.9% of patients with dysphagia, with 64.7% on thin fluids, 35.3% on thick fluids, 11.8% on pureed diet, and 5.9% on soft diet. Multivariate analysis of variance (MANOVA) indicated pharyngeal contraction and swallowing response had significant effect on thick fluids (p =.002), thin fluids (p =.017), and soft diet (p =.031). Conclusion. Silent aspiration of thin fluids is a common occurrence in dysphagic NPC post-RT, with least aspiration noted on soft diet. Considering the high incidence of silent aspiration, instrumental assessment in this cohort is crucial. © 2010 Wiley Periodicals, Inc. Head Neck, 2010