Abstract:  Objective To explore the influence of intensity-modulated radiotherapy（IMRT） on cognitive function in patients with nasopharyngeal carcinoma（NPC）. Methods Between December 2012 and May 2013， patients with pathologically diagnosed NPC scheduled to receive IMRT were included.Dose-volume histograms of the temporal lobes were obtained for every patient， and the Das Naglieri Cognitive Assessment System（DN-CAS） was used to assess cognitive function before and after radiotherapy.Differences in cognitive function between patients were analyzed using the paired t-test. Results Mean radiation dose was（17.5±7.3）Gy to the left temporal lobe and（18.2±6.8）Gy to the right temporal lobe. Standardized scores on all DN-CAS subtests（Planning， Attention， Simultaneous， and Successive cognitive processes） were similar before and after radiotherapy（P＞0.05）. Conclusions IMRT did not induce any acute changes in cognitive function of NPC patients. Future studies with longer follow-up should further evaluate the poten-tial effects of radiotherapy on the cognitive function of NPC patients.

Key words: Nasopharyngeal neoplasm, Radiotherapy, Intensity-modulated, Cognitive function