Intensity modulated radiation therapy for 111 cases of primitive nasopharyngeal carcinoma

Objective To evaluate the effects of intensity modulated radiation therapy(IMRT) for the treatment of primitive nasopharyngeal carcinoma.Methods A total of 111 patients with primitive nasopharyngeal carcinoma received IMRT were enrolled,included 76 males and 35 females,who were aged 22-71 years with a median age of 47.Nineteen patients were in stage Ⅰ,58 patients stage Ⅱ,32 patients stage Ⅲ and 2 patients stage Ⅳa.The prescribed dose 60-65 Gy was delivered to plan tumor volume(PTV),lessened irritation field and increased dose of 70-75 Gy were given when tumor volume was reduced.The dose of IMRT at middle and low neck was 65-70 Gy,52 Gy for supraclavicular area,36.5 Gy for brainstem and spinal cord,47.2 Gy and 43.4 Gy for left and right optic nerve,40.1 Gy and 39.6 Gy for left and right parotid,and less than 30 Gy for parotid,respectively.Results The median follow-up time was 38-month,local and lymph nasopharyngeal carcinoma reoccurred in 22 patients.The 1-year and 2-year local recurrent rates were 5.4 % and 14.4 %.The 1-year,2-year and 3-year survival rates were 98.2 %,94.6 % and 85.6 %,respectively.Mucositis,bone marrow suppressing and xerostomia were the most common acute reactions.Grade Ⅰ,Grade Ⅱ and Grade Ⅲ mucositis were 22.5 %,44.1 % and 33.3 % respectively;Grade Ⅰ,Grade Ⅱ and Grade Ⅲ bone marrow suppressing were 31.5 %,34.2 % and 14.4 %,respectively;the radiation cranial injury was not observed in all patients.Conclusion It is demonstrated that IMRT could achieve satisfactory dose distribution for nasopharyngeal carcinoma,it could also protect normal tissues and improve local control rate.IMRT could become the standard method for the treatment of nasopharyngeal carcinoma.