鼻咽癌放疗后视神经病变的临床研究

Radiation-induced optic neuropathy in patients with nasopharyngeal carcinoma

目的探讨鼻咽癌放疗后视神经病变（RON）的临床特点及其发病相关的可能危险因素。方法回顾性分析中山大学孙逸仙纪念医院自1997年1月至2011年1月收治的22例鼻咽癌放疗后RON患者的病历资料，总结其临床表现、眼科检查及影像学表现。结果视力下降甚至失明是RON最常见的表现；18例于首程放疗后出现，2例于首程放疗过程中出现，2例于再程放疗中出现，共8眼失明．27眼视力下降。14例患者眼科检查发现眼底视神经萎缩改变。影像学检查发现视神经增粗30眼，视神经萎缩5眼。照射剂量≥70Gy时患者RON的发生率高于照射剂量〈70Gy的患者，差异有统计学意义（P〈0．05）。结论鼻咽癌放疗可引起视神经损伤，并常伴视力、视野、视觉诱发电位异常及影像学表现。RON的发生与放射野、放射剂量有关。常规进行眼科及影像学检查进行早期诊断具有重要意义。

Objective To investigate the characteristics of radiation-induced optic neuropathy （RON） in patients with nasopharyngeal carcinoma after radiotherapy, and explore its risk factors. Methods A retrospective study was performed on the clinical data of 22 RON patients with nasopharyngeal carcinoma after radiotherapy, admitted to our hospital from January 1997 to January 2011. Their clinical manifestations, eye examinations and cranial MRI data were concluded. Results Visual deterioration, or even, blindness, was the most common manifestation. RON occurred after the initial radiotherapy in 18 cases, and during the initial radiotherapy in 2 cases. And 2 cases developed RON in re-irradiation for recurrences. Blindness developed in 8 eyes, and decreased vision occurred in 27 eyes; 14 patients displayed retinal optic nerve atrophy in the eye examinations. Typical radiological imaging of the skull showed optic nerve enlargement in 30 eyes, optic nerve atrophy in 5 eyes; and the incidence of optic neuropathy was high when radiation dose was over 70 Gy. Conclusion RON may occur in nasopharyngeal carcinoma patients following radiotherapy, having vision disorders, visual field changes, abnormal visual evoked potential and typical cranial imaging performances; the occurrence of RON may be correlated with radiation field and radiation dose; routine eye and imaging examination is of great significance.