The relationship between radiotherapy dose for nasopharyngeal carcinoma and corneal endothelial cell loss

Objective To evaluate the implementation between radiotherapy dose for NPC and corneal endothelial cell loss.Methods A retrospective study was made for 103 patients who had received radiation therapy for nasopharyngeal carcinoma between January 2007 and December 2009 in Huai'an First People's Hospital,Nanjing Medical University.The patients were divided into four groups according to different radiation doses,and the corneal endothelial cell densities were recorded for each group before treatment and 1 day,1 week,1 month,6 months,1 year,and 2 years after treatment,the effects that radiation dose on corneal endothelial cells through analyzing the changes of corneal endothelial cell densities between pre-treatment and post-treatment were assessed.Results The difference of age was not statistically significant (F 1.90,P 0.1353).The corneal endothelial cells was slightly reduced when the radiation dose was less than 50Gy (group A and B),and which could be restored to the pre-treatment level during follow-up.The corneal endothelial cells was significantly reduced when the radiation dose was more than 50Gy (group C and D),and which could be restored to the pre-treatment level during follow-up.Conclusions Reduction in corneal endothelial cells associated with radiation dose,when the threshold of radiation dose is reached,the corneal endothelial cells begin to reduce,or even evolved severe corneal disease,so corneal protection and actively prevention and treatment is very necessary. Key words: Nasopharyngeal carcinoma;  Radiotherapy;  Corneal endothelial cells