INTRODUCTION
NPC, toxicities
NASOPHARYNGEAL CARCINOMA, ORAL MUCOSITIS, COMPLICATION
Radiotherapy serves as the main therapy for nasopharyngeal carcinoma (NPC). However, radiation‐related toxicities cannot be avoided, for example, oral mucositis during radiotherapy is a common complication in NPC patients.The normal operation during a cell cycle is mainly regulated by cyclins, protein‐dependent kinases, and protein‐dependent kinase inhibitors.Therefore, we designed a prospective randomized controlled study to observe the severity of oral mucositis and oral pain caused by radiotherapy in a corresponding time window of different cycles of oral mucosal cells and explore a new method to reduce radiation‐induced oral mucositis in NPC patients.