鼻咽癌海绵窦侵犯调强放疗后放射性颞叶损伤的临床分析

目的 探讨海绵窦受侵的局部晚期鼻咽癌行调强放疗后发生放射性颞叶损伤的临床特征、MRI表现、放疗剂量和预后。方法 回顾性分析2006年8月至2011年9月收治的10例行根治性调强放疗的海绵窦受侵局部晚期鼻咽癌患者，统计放疗计划中患侧颞叶受照射的总体积和剂量体积D1 ml、Dmax、Dmean，并随访所有患者治疗后的情况，分析发生放射性颞叶损伤后的临床特征、MRI表现及预后。结果 10例患者均行根治性调强放疗，患侧颞叶受照射的总体积为（104.31±13.091） ml，D1 ml为（78.657±2.918）Gy，Dmax为（78.298±3.498）Gy，Dmean为（29.488±8.891）Gy。全组患者于治疗后2～4年出现放射性颞叶损伤，其MRI表现均为T1WI高信号强化结节或片状强化灶，T2WI伴有不同程度的水肿带。随访至2016年8月，2例患者死亡；2例临床症状较重，迁延时间长，治疗后症状改善不明显，且MRI仍可见强化灶和水肿带；2例患者经对症处理后临床症状及MRI检查均明显好转；4例患者病情趋于稳定，其中2例患者的恢复期MRI提示小囊性灶形成。结论 海绵窦受侵的局部晚期鼻咽癌患者行调强放疗后发生放射性颞叶损伤与肿瘤侵犯范围、靶区勾画范围、颞叶受照射的体积及剂量有关。

Clinical analysis of radiation induced temporal lobe injury after intensity modulated radiation in nasopharyngeal carcinoma patients with cavernous sinus invasion

Objective To investigate clinical features,MRI findings,radiation volume and dose,and prognosis of irradiated temporal lobe injury in local advanced nasopharyngeal carcinoma infilatrating cavernous sinus after intensity modulated radiation therapy (IMRT).Methods From Aug 2006 to Sep 2011,ten patients with cavernous sinus invasion in locally advanced nasopharyngeal carcinoma receiving radical IMRT were retrospectively analyzed.The total volume,dose volume D1 ml,Dmax and D of irradiated ipsilateral temporal lobe in radiotherapy planning were examined.Clinical features,MRI findings and prognosis of these patients after treatment were investigated.Results The irradiated ipsilateral temporal lobe total volume and dose volume of IMRT of the 10 ten patients were as follows.The total volume was (104.31 ± 13.091)ml,D1 ml was (78.657±2.918)Gy,D was (78.298± 3.498)Gy and D was (29.488±8.891) Gy.The radiation induced temporal lobe injury presented 2-4 years after radiation in the 10 followed-up patients.MRI findings showed T1 WI with high signal reinforced nodular lesions or sheet strengthening and T2WI with varying degrees of edema.Till August 2016,2 patients died;2 patients were with heavy symptoms and the symptoms were not improved obviously after treatment,and meanwhile,MRI showed enhancement and edema;2 patients were significantly improved in clinical symptoms and MRI findings after symptomatic treatment;4 patients with stable disease and MRI of 2 patients showed small recovery cystic foci formation.Conclusion The incidence of irradiated temporal lobe injury in cavernous sinus of locally advanced nasopharyngeal carcinoma after IMRT were associated with the area of tumor invasion,the scope of target delineation and the irradiated volume and dose.