放射敏感鼻咽癌个体化放射治疗的可行性研究

目的比较放射敏感性鼻咽癌(NPC)个体化放射治疗与常规放射治疗的长期疗效和毒副作用,以评估降低照射剂量和同期加量照射治疗放射敏感性NPC的可行性。方法选择2005～2006年常规放疗至40Gy/20次经CT和/或MR评估鼻咽原发肿瘤完全消退的64例放射敏感鼻咽癌患者,按照T、N分期随机分为个体化照射(IRT)组和常规剂量照射(CRT)组,IRT采用降低总剂量和对T3期患者同期加量照射,CRT采用常规剂量和常规分割照射,分别予鼻咽原发肿瘤放疗根治剂量60～67.6Gy/30～32次/6～6.5周和66～78Gy/33～35次/6.5～7.5周。结果IRT组的1、2、3年局部控制率分别为96.7%、90.0%、86.7%,CRT组为93.8%、90.6%、87.5%(P>0.05)。IRT组的1、2、3年生存率分别为100%、93.3%、83.3%,CRT组为96.9%、93.8%、84.4%(P>0.05)。急性放射毒性反应主要为咽黏膜炎及唾液腺分泌唾液减少导致口腔干燥,两组差异无统计学意义(P>0.05);晚期的放射损伤IRT组的咽黏膜萎缩、张口受限及放射性中耳炎发生率明显低于CRT组(P<0.05),而放射性脑病及口腔干燥两组发生率相似(P>0.05)。结论放射敏感NPC患者适当降低照射剂量和采用同期加量照射的个体化放射治疗是能够达到与常规剂量照射的根治性放射治疗相当的疗效,而且可一定程度上降低脑、颞颌关节、中耳等重要器官晚期放射损伤的发生率,值得进一步深入研究。

Clinical Study on Individual Radiotherapy for Patients with Nasopharyngeal Carcinoma of High Radiation-Sensitivity

Objective To investigate the feasibility of individual radiotherapy(IRT) for patients with nasopharyngeal carcinoma of high radiation-sensitivity via caparison of long-term effect,toxicities between individual and conventional radiotherapy(CRT).Methods From Jan,2005 to Dec,2006,64 patients with nasopharyngeal carcinoma,who achieved complete remission of primary tumor by CT/MR evalua tion after 40 Gy/20 fractions conventional irradiation,were eligible to this study.Based on T and N stage,all patients were randomized to IRT group by decreased total dose and simultaneous boost,and CRT group with total dose of 60～67.6 Gy/30～32 fractions/6～6.5 weeks and 66～78 Gy/33～35 fractions/6.5～7.5 weeks respectively.Results 1,2,3 years local control rate of IRT and CRT groups were 96.7%、 90.0%、 86.7% and 93.8%、 90.6%、 87.5%(P >0.05) respectively.And 1,2,3 years overall survival rate of IRT and CRT groups were 100%、 93.3%、 83.3% and 96.9%、 93.8%、 84.4%(P >0.05) respectively.Two groups patients underwent similar acute radiation reactions of mocusities and xe rostomia and late radiation injuries of radiation induced encephalopathy and long-term xerostomia(P >0.05),but the occurrence of late radia tion injuries of mucosa atrophy,open-mouth difficulty and tympanitis in IRT was significantly lower than those of CRT(P <0.05).Conclusion IRT can achieve equivalent long-term effect as CRT for patients with nasopharyngeal carcinoma of high radiation-sensitivity,and can decrease the occurrence of late radiation injuries of temporal-mandible joint and middle ear as well,which is worthy of further study.