鼻咽癌N_1患者对侧下颈调强靶区优化的临床研究

Clinical Study of Contralateral Lower Neck Intensity-modulated Radiotherapy Target Volumn Optimization in Patients with N_1-staged Nasopharyngeal Carcinoma

[目的]研究鼻咽癌N_1患者对侧下颈调强放疗靶区优化的可行性。[方法]回顾性研究收治的122例AJCC分期为N_1的初治鼻咽癌患者,在多模态影像指导下进行对侧下颈调强放疗靶区的优化。[结果] 122例患者中有100例对侧下颈未预防照射,22例对侧下颈预防照射。全组随访时间为27～69个月,中位随访时间40个月。3年无疾病生存率、无远处转移率及总生存率分别为90.6%、91.1%、96.5%。全组共有3例出现颈淋巴结复发,均为高剂量区复发。预防照射的22例患者中,15例对侧中下颈有≥5mm但<10mm的稍大淋巴结,即可疑阳性淋巴结,放疗后这些未达到诊断标准的淋巴结10例缩小,5例无明显变化。[结论]鼻咽癌N_1患者对侧下颈不进行预防照射是安全的,但对于少数影像显示对侧中下颈存可疑阳性淋巴结时,需要结合多模态影像及重复定位CT的观察结果进行优化。

[Objective] To study the feasibility of target volumn optimization for contralateral lower neck among patients diagnosed as N1-staged nasopharyngeal carcinoma(NPC) treated with intensity-modulated radiotherapy(IMRT). [Methods] A retrospective analyze was performed in 122 patients initially diagnosed as NPC with an AJCC staging N1. Target volumn was guided by multimodality imaging examination before IMRT and contralateral lower neck was optimized during radiation. [Results] A total 100 of 122 cases were administrated with contralateral lower neck-sparing IMRT,while the rest 22 cases received conventional radiotherapy with contralateral lower neck irradiated prophylactically. During a median of 40 months follow-up(range:27~69 months),3cases of the entire cohort experienced cervical lymph node recurrence in high-dose area,and 15 of 22 patients irradiated conventionally without optimization on neck were found slightly larger lymph nodes(≥5mm and <10mm) in contralateral middle and lower neck. These nodes of the 15 pations were considered as suspicions postitive from NPC and were salvage re-irradiated. After reirradiation,nodes of 10 cases remainde stable. The 3-years disease-free survival(DFS) rate,distant metastasis-free(DMFS) rate and overall survival(OS) rate were 90.6%,91.1% and 96.5%,respectively. [Conclusion] Contralateral lower neck-sparing IMRT for staged-N1 NPC is feasible while careful patients selection guided by multimodal imaging and repeated positioning CT observation is necessary.