鼻咽癌侵犯周围结构与肿瘤分期关系的MRI研究

MRI study on the relationship between the invasion patterns and staging of nasopharyngeal carcinoma

目的 应用MRI探讨鼻咽癌侵犯周围结构的规律及其与肿瘤T分期的关系.方法 回顾性分析1573例经病理证实的鼻咽癌初诊患者,根据2008年鼻咽癌T分期,观察鼻咽癌向周围结构侵犯的MRI表现和规律.对鼻咽癌周围不同方向结构的侵犯率均采用Z检验分析.结果 鼻咽癌对周围结构的侵犯：咽颅底筋膜1299例（82.58%）、咽旁间隙1090例（69.29%）、鼻腔304例（19.33%）、口咽49例（3.12%）、颈动脉间隙514例（32.68%）、翼内肌661例（42.02%）、翼外肌210例（13.35%）、颅底骨质943例（59.95%）、颅神经630例（40.05%）、鼻窦242例（15.38%）.T分期分布：T1期为242例（15.38%）,T2期为288例（18.31%）,T3期为410例（26.06%）,T4期为633例（40.24%）.鼻腔受累的病例中90.46%（275/304）合并T3以上的结构受累;口咽受累均伴有T3以上结构受累;翼内肌受累的病例中69.14%（457/661）伴有T4结构侵犯;鼻窦受累的病例中92.15%（223/242）伴有T4结构侵犯.鼻咽癌侵犯周围结构的模式为向侧方（1299例）多于向上（943例）侵犯（Z=14.025,P＜0.01）;向侧方侵犯多于向下（49例）（Z=45.032,P＜0.01）;向上侵犯多于向下（Z=34.301,P＜0.01）;向前侵犯（304例）多于向下（Z=14.404,P＜0.01）.结论 鼻咽癌侵犯周围结构的模式为向侧方侵犯多于向上;向侧方侵犯多于向下;向上侵犯多于向下;向前侵犯多于向下.

Objective To investigate the peri-nasopharyngeal invasion patterns of nasopharyngeal carcinoma （NPC） on MRI and its relationship with tumor staging. Methods One thousand five hundred and seventy-three patients with newly diagnosed NPC which were histo-pathologically proved were retrospectively studied. The MRI manifestations and invasion patterns of the NPCs were elevated according to the 2008 Tstaging system of NPC. Z test was used to analyze the rate of adjacent structures invasion in NPCs. Results The structures invaded by NPCs included pharyngobasilar fascia in 1299 cases （82. 58% ）; parapharyngeal space, 1090 （ 69. 29% ）; nasal cavities, 304 （ 19. 33% ）; oropharynx, 49 （ 3. 12% ）; carotid space,514（32. 68% ）; medial pterygoid muscle, 661 （42. 02% ）; lateral pterygoid muscle, 210（ 13. 35% ）; skull base bones, 943（59. 95% ）; cranial nerves, 630（40. 05% ） and paranasal sinuses, 242 （ 15.38% ）. The T-stage distribution was T1, 242 cases （ 15.38% ）; T2, 288 （ 18. 31% ）; T3, 410 （26. 06% ） and T4,633 （40. 24% ）. Among the cases with nasal cavities invasion, 90. 46% （275/304）showed the involvement of the structures seen in T3 or T4 stage, which was found in all cases with oropharynx invasion. In addition,69. 14% （457/661） of cases with medial pterygoid muscle invasion and 92. 15% （223/242） of cases with paranasal sinuses invasion showed the involvement of structures seen in T4 stage. As for the invasion patterns of NPC, the lateral invasion of pharyngobasilar fascia was more frequent than upward invasion of skull base （Z = 14. 025, P ＜ 0. 01 ） and downward invasion of oropharynx （ Z = 45.032, P ＜ 0. 01 ）, and the downward invasion of oropharynx was less frequent than upward invasion of skull base （ Z = 34. 301, P ＜ 0. 01 ） and forward invasion of nasal cavities （ Z = 14. 404, P ＜ 0. 01 ）. Conclusion NPC has a predilection of lateral invasion rather than upward and downward invasion, and its upward and forward invasion are more common than downward invasion.