基于MRI及IMRT下的鼻咽癌新T分期研究

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。

A new T staging system for nasopharyngeal carcinoma based on magnetic resonance imaging and intensity-modulated radiotherapy

Objective 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.