Abstract: Objective To investigate the characters of chronic sinusitis induced by radiotherapy for nasopharyngeal carcinoma. Methods The clinical data of 40 chronic sinusitis patients induced by radiotherapy for nasopharyngeal carcinoma (the radiotherapy group) and 40 common chronic sinusitis patients (the control group) enrolled in our department from January 2011 to May 2013 were retrospectively analyzed. All patients were measured the symptom visual analysis scale (VAS) and took endoscopic examination and sinus CT scanning. A total of 18 patients of the radiotherapy group and 36 patients of the control group accepted endoscopic surgery, during the operation, purulent secretion in the maxillary was exacted and bacterial culture was done. Results As to the VAS, nasal secretion was significantly more severe in the experimental group (6.5±1.2) in comparison with the control group (5.3±1.0, P<0.05). As to the endoscopic finding, more dry and more curst in the postior nasal cavity and nasopharynx, the Lund-Kenndy score was 6.2±1.1 in the experimental group vs 4.7±0.7 in the control group. The main reasons laid in high CT scores and high involved rates of ostiomeatal complex, frontal sinus, maxillary sinus and anterior ethmoid sinus. Conclusion The characters of chronic rhinosinusitis caused by radiotherapy are quite different from those of the common chronic sinusitis. The mechanism of chronic sinusitis induced by radiotherapy prefers to obstruction of the ostium or dysfunction of the cilia continued with bacterial infection.

Key words: Complications, Chronic sinusitis, Nasophrangeal carcinoma, Radiotherapy