目的 探讨咀嚼肌间隙侵犯对鼻 咽癌预后的影响及其在T分期中的意义。 方法 回顾性分析经病理确诊的442例初 诊无远处转移鼻咽癌患者的临床及影像资 料，将侵犯翼内肌的病例归为T3期，咀嚼 肌间隙除外翼内肌病例归为T4期，将颅底 骨质、颅内、鼻窦等侵犯病例作为对照研 究。比较此种分期方法对鼻咽癌患者预后 的影响及意义。以总生存率、无局部复发 生存率及无远处转移生存率为主要预后指 标。应用Kaplan-Meier法分析，差异比 较应用Log-rank检验。采用双侧检验， P<0.05为差异有统计学意义。结果 T3翼 内肌组与T4咀嚼肌间隙除外翼内肌组总生 存率差异有统计学意义(P=0.02)，两者 无局部复发生存率、无远处转移生存率 差异无统计学意义(P=0.55；P=0.09)。 T3翼内肌组与T4颅内、鼻窦等组总生存 率、无远处转移生存率差异有统计学意义 (P=0.02；P=0.01)。T3翼内肌组与T3颅底 骨质组总生存率、无局部复发生存率及 无远处转移生存率差异均无统计学意义 (P>0.05)。T3与T4分期总生存率、无远处 转移生存率差异有统计学意义(P=0.001， P=0.004)，临床TNM分期Ⅲ期、Ⅳa期总生 存率、无局部复发生存率、无远处转移 生存率差异均有统计学意义(P=0.002， P=0.025，P=0.003)。结论 咀嚼肌间隙侵 犯影响鼻咽癌患者的总生存率，侵犯咀嚼 肌间隙部位不同对预后的影响有一定差 异。

Objective To analyze the prognosis of masticator space involvement in NPC and evaluate the value of masticator space involvement in T-staging. Methods All the biopsy-proven newly diagnosed non-metastatic NPC 442 patients were collected. Medial pterygoid muscle involvement were classified as stage T3 group. Masticator space (except for medial pterygoid muscle) were classified as stage T4 group. Skull base, intracranial and paranasal sinuses involvement were used as a control group. The following endpoint were assessed:overall survival rate (OS), local recurrence-free survival (LRFS), distant metastasis-free survival (DMFS). Using Kaplan-Meier method, the differences were compared using the Log-Rank test. A two-sided test, P<0.05 had significant difference. Results Overall survival of T3 medial pterygoid muscle group and T4 masticator space except for the medial pterygoid muscle group was statistically significant (P=0.02), local recurrence-free survival and distant metastasis-free survival rates were not statistically significant between them(P=0.55, P=0.09). overall survival, distant metastasis free survival rate of T3 medial pterygoid muscle group and T4 of intracranial sinus group were statistically significant (P=0.02, P=0.01). Overall survival rate, local relapse-free survival and distant metastasis-free survival were not statistically significant between T3 medial pterygoid muscle group and T3 of skull base (P>0.05). Overall survival, distant metastasisfree survival rate of staging T3 and T4 were statistically significant (P=0.001, P=0.004). Overall survival rate, local relapse-free survival and distant metastasis-free survival rate of clinical-stage III and IVa were statistically significant (P=0.002, P=0.025, P=0.003). Conclusion Masticator space involvement in NPC influenced the rate of overall survival, and if the infiltration of masticator space is different, the prognosis is different.