A detailed dosimetric comparative study of IMRT and VMAT in normal brain tissues for nasopharyngeal carcinoma patients treated with radiotherapy

Background Radiotherapy (RT) is the primary treatment for nasopharyngeal carcinoma (NPC). However, it can cause implicit RT-induced injury by irradiating normal brain tissue. To date, there have been no detailed reports on radiated exact location in brain, corresponding radiation dose, and their relationship. Methods We analyzed 803 Chinese NPC patients treated with RT used a CT template Montreal Neurological Institute (MNI) space to compare group differences dose distribution different technologies (IMRT or VMAT). Results Brain regions that received high doses (>50 Gy) of were mainly located parts temporal limbic lobes, where radioactive damage often occurs. accepted higher IMRT near anterior region tumor, while VMAT posterior tumor. No significant difference was detected between T1 stage patients. For T2 patients, widely distributed, showing advantage protecting T3 showed an superior gyrus lobe, cerebellum. T4 disadvantage These results indicate own advantages sparing organs at risk (OARs) T stages RT. Conclusion Our approach analyzing dosimetric characteristics standard MNI provides greater convenience toxicity dosimetry analysis localization accuracy. Using this method, we found interesting from previous reports: tissue