摘要目的：建立一个基于MRI并与IMRT相适应的鼻咽癌新T分期系统。方法回顾分析2008—2010年我院基于MRI并接受IMRT的608例初治无转移鼻咽癌患者资料，按鼻咽癌第7版UICC／AJCC分期系统进行分期。 Kaplan?Meier法计算相关生存率及Logrank检验，Cox法多因素分析。现行UICC／AJCC分期系统存在不足，在此基础上建立新鼻咽癌T分期系统，并对新T分期系统合理性进行评价。结果5年随访率为94?5％，5年OS、DFS、LRFS、DMFS分别为81?5％、80?1％、86?0％、81?1％。单因素及多因素分析结果显示鼻咽、咽旁间隙、颅底解剖结构均为影响患者OS率因素（ P＝0?000—0?045）。根据风险差异性及生存曲线分布提出新T分期标准：T1期：侵袭鼻咽、咽旁间隙、口咽、鼻腔、颅底、翼内肌；T2期：侵袭翼外肌、鼻窦、眼眶、颅内、颞下窝、颅神经。推荐新 T分期系统LRFS曲线及OS曲线均能很好地拉开。结论推荐新T分期系统能较客观地预测鼻咽癌患者预后，可作为鼻咽癌临床新分期探索性的尝试。

abstractsObjective To establish a new T staging system for nasopharyngeal carcinoma ( NPC) based on magnetic resonances imaging ( MRI) and intensity?modulated radiotherapy ( IMRT) . Methods A retrospective analysis was performed on the clinical data of 608 patients who were newly diagnosed with non?metastatic NPC by MRI and treated with IMRT in our hospital from 2008 to 2010. All patients were staged according to the 7th edition of the UICC/AJCC staging system for NPC. The survival rates were calculated using the Kaplan?Meier method and analyzed using the log?rank test. The Cox regression model was used for multivariate analyses. To deal with the deficiency in the current UICC/AJCC staging system, a new T staging system for NPC was established and systematically evaluated. Results The 5?year follow?up rate was 94?5%. The 5?year overall survival (OS), disease?free survival, local relapse?free survival (LRFS), and distant metastasis?free survival rates were 81?5%, 80?1%, 86?0%, and 81?1%, respectively. The univariate and multivariate analyses showed that the anatomic structures of nasopharynx, parapharyngeal space, and skull base were influencing factors for the OS rate (P=0?000?0?045). New T staging criteria were proposed based on the risk differences and survival curves:stage T1:invasion of the nasopharynx, parapharyngeal space, oropharynx, nasal cavity, skull base, and internal pterygoid muscle;stage T2:invasion of the external pterygoid muscle, paranasal sinus, intracalvarium, infratemporal fossa, and cranial nerves. The proposed T staging system achieved a good separation in both OS and LRFS curves. Conclusions The proposed new T staging system gives an objective prognostic prediction in patients with NPC, which provides an exploratory attempt toward a new clinical staging system for NPC.