ABSTRACT
The incidence of middle ear effusion due to radiotherapy of head and neck carcinoma is as high as 16—26 percent.Irradiation causes tissue reactions such as congestion,edema, mucositis and fibrosis, which is responsible for the postirradiation tubal dysfunction. The tubal function is worst 6 months after radiotherapy . The cancer disappears after radiotherapy, but the tubal dysfunction still would happen if inflammation and local radiotherapy-induced oedema exist. The tubal function improved at 5 years after radiotherapy if the irradiation dosage is below 70 Gy in patients with nasopharyngeal carcinoma. The mean radiation dosage in the ears with patulous tubes compared for tubals with normal opening has no significant difference. The incidence of otorrhea is very high 2 years after radiotherapy in patients treated by myringotomy and ventilation tube insertion. The tubal function may become normal without treatment and patulous tubes may develope 5 to 10 years after radiotherapy.