Analysis of risk factors of outcomes of radiation induced-brain injury after IMRT in nasopharyngeal carcinoma

Abstract

Objective To explore the risk factors influencing the outcomes of radiation brain injury after intensity-modulated radiotherapy (IMRT) in patients diagnosed with nasopharyngeal carcinoma. Methods Clinical data of 1 300 nasopharyngeal carcinoma patients treated with IMRT in our hospital during 2006 and 2013 were retrospectively analyzed. Fifty-eight patients presented with radiation brain injury after IMRT. MRI data of these patients during 3-24 months follow-up were collected. The clinical efficacy in the treatment of radiation brain injury was evaluated according to RECIST guidelines. Results Forty-six patients with intact follow-up data were enrolled. The median latency of radiation brain injury was 34 months. Patients were divided into the response (CR+ PR) and non-response groups. The risk factors influencing the response rate during 10-12 months and 18-24 months were identified and analyzed. Univariate analysis demonstrated that gender, age, smoking history, T stage, and high-intensity treatment exerted no significant effect upon the objective remission rate during these two time intervals periods. Patients treated with gangliosides obtained high response rate. The response rate was 68.8% in 10-12 months (P=0.000), and 81.8% in 18-24 months (P=0.008). Multivariate analysis revealed that use of gangliosides was a favorable factor for mitigating radiation brain injury in two time intervals (OR=19.8 and 13.5; P=0.001 and 0.005). Conclusions Use of gangliosides probably accelerates the healing of radiation brain injury, whereas the clinical efficacy remains to be elucidated by prospective clinical trials. Key words: Radiation induced brain injury; Clinical outcome; Ganglioside; Nasopharyngeal neoplasm/intensity-modulated radiotherapy