调强放疗时代原发肿瘤体积对鼻咽癌预后的影响

Impacts of primary gross tumor volume on the prognosis of nasopharyngeal carcinoma in the era of intensity modulated radiation therapy

目的探讨原发肿瘤体积(GTVp)对调强放射治疗(IMRT)后鼻咽癌(NPC)患者预后的影响。方法选取2008年1月~2009年8月在福建省肿瘤医院行调强放疗的365例非转移NPC患者为研究对象。根据ROC曲线分析结果确定与生存率相关的GTVp最佳截点。采用Kaplan-Meier法计算生存率,log-rank法对比生存,Cox回归模型多因素分析,P<0.05为差异有统计学意义。结果GTVp<48mL vs.≥48mL的5年总生存率(OS)、5年局部无复发生存率(LRFS)、5年无远处转移生存率(DMFS)、5年无病生存率(DFS)分别为89.0%vs.71.2%(P=0.000)、90.5%vs.81.4%(P=0.022)、90.2%vs.80.7%(P=0.012)、84.3%vs.67.3%(P=0.000)。多因素分析结果显示,GTVp是IMRT治疗后NPC患者OS、LRFS、DFS的独立预后因素。结论GTVp是影响IMRT治疗后NPC患者预后的独立危险因素,TNM分期系统与GTVp相结合可以提高预后评估能力。

Objective To investigate the impacts of primary gross tumor volume(GTVp)on the prognosis of patients with nasopharyngeal carcinoma(NPC)after intensity modulated radiation therapy(IMRT).Methods A total of 365 patients with non-metastatic NPC admitted to Fujian Provincial Cancer Hospital and treated with IMRT from January 2008 to August 2009 were selected as the objects in this research.According to the results of ROC curve analysis,the optimal cut-off point of GTVp related to survival rate was determined.Kaplan-Meier method was applied to calculate survival rate,log-rank method was applied to compare survival rate,and Cox regression model was applied for multivariate analysis.Meanwhile,P<0.05 was considered to be statistically significant.Results The 5-year overall survival(OS)rate,5-year local recurrence-free survival(LRFS)rate,5-year distant metastasis-free survival(DMFS)rate and 5-year disease-free survival(DFS)rate of GTVp<48mL vs.≥48mL were 89.0%vs.71.2%(P=0.000),90.5%vs.81.4%(P=0.022),90.2%vs.80.7%(P=0.012),and 84.3%vs.67.3%(P=0.000).Multivariate analysis result showed that GTVp was an independent prognostic factor of OS,LRFS and DFS in NPC patients after IMRT.Conclusion GTVp is an independent risk factor impacting the prognosis of patients with NPC after IMRT treatment.Meanwhile,TNM staging system combined with GTVp can improve the ability of prognosis evaluation.