Abstract:    Background and purpose: Currently, subjective questionaire is the most frequently used methods to evaluate swallowing dysfunctions after radiotherapy in nasopharyngeal carcinoma patients, while lacking of effective objective examinations. This study aimed to explore effective methods to evaluate swallowing dysfunctions after radiotherapy in nasopharyngeal carcinoma patients, and gain knowledge of the incidence and severity of swallowing dysfunctions. Methods: From Oct. 2013 to Dec. 2013, 128 consecutive outpatients with previously treated nasopharyngeal carcinoma received esophageal barium fluoroscopy examination at there regularly follow-ups to evaluate swallowing function. Among these patients, 89 were primary treated with intensity modulated radiation therapy (IMRT) and 39 with conventional radiotherapy (CRT). In this study, each patient received esophageal barium fluoroscopy examination for 3 times with thin, thick and pasty barium and were dynamically observed using X-ray fluoroscopy from front and lateral direction. Swallowing dysfunctions were defined as follows: ①The bolus could not be swallowed and blocked in the mouth; ②The dilute barium diverted to the glottis or trachea; ③Residual barium delayed in the pyriform sinus and vallecula; ④The movement of the hyoid bone or epiglottis were restricted; ⑤Bolus prolong through the pharynx; ⑥Barium slowed down when went though the esophageal entrance. Results: Of the 128 patients, incidence of dysphagia was 60.2% for the entire cohort, 52.8% for IMRT group and 76.9% for CRT group. Incidence of dysphagia for IMRT group was significantly lower than CRT group (P=0.018). Dysphagia incidence within 1 year, 1 to 2 years and more than 2 years after RT were 63.1%, 33.3% and 69.0%, respectively (P=0.019). Conclusion: There was a high incidence of swallowing dysfunction for the nasopharyngeal carcinoma patients treated with radiotherapy and dysphagia incidence decreased when treated with IMRT. Esophageal barium fluoroscopy examination is objective method to evaluate the incidence and severity of the swallowing dysfunction.

Key words: Nasopharyngeal carcinoma, Radiotherapy, Dysphagia, Esophageal barium fluoroscopy