三维适形调强放射疗法治疗鼻咽癌的急性反应和晚期损伤

Acute and late normal tissue toxicity study of nasopharyngeal carcinoma patients receiving intensive modulated radiation therapy

目的 观察三维适形调强放射疗法（IMRT）治疗鼻咽癌的急性反应和晚期损伤.方法 收集2008年3月至2011年1月新疆维吾尔自治区人民医院经病理组织学确诊的初治有完整资料的鼻咽癌患者60例,所有患者采用IMRT治疗（调强放疗组）;另外选择同期在本院住院采用常规放疗治疗的鼻咽癌患者65例（常规放疗组）.调强放疗组患者均按照根治性放疗,根据病变勾画靶区及需保护的正常重要器官,定义大体靶区鼻咽大体肿瘤靶体积、临床靶区、计划靶区.按照美国肿瘤放射治疗协作组（RTOG）急性放射损伤分级标准对急性反应和晚期损伤进行评价,并对2组患者急性期皮肤的放疗毒性反应进行统计学分析.结果调强放疗组皮肤急性反应1级发生率85.0%（51/60）;2级发生率11.7%（7/60）;3级发生率3.3%（2/60）.2组患者急性期皮肤放疗毒性反应比较,常规放疗组Ⅲ度毒性反应1例（1.5%）;Ⅰ＋Ⅱ度毒性反应64例（98.5%）;调强放疗组Ⅲ度毒性反应2例（3.3%）.2组Ⅲ度毒性反应比较,差异有统计学意义（P〈0.05）.结论 与常规放疗比较,IMRT治疗鼻咽癌对正常组织器官有较好的保护作用,可降低放疗急性反应和晚期损伤发生率.

Objective To observe the acute and late normal tissue toxicities of nasopharyngeal carcinoma （NPC） treated with intensity modulated radiation therapy （IMRT）. Methods From March 2008 to January 2011, 60 nasopharyngeal carcinoma patients confirmed by histologically in Xinjiang uygur autonomous region people＆#39;s hospital were collected. All patients were treated by IMRT（IMRT group）. Sixty-five nasopharyngeal carcinoma patients treated by conventional radiotherapy were selected as conventional radiotherapy group. The GTV, CTV and PTV were irradiated by IMRT technique.The lower neck and the supraclavicular fossae were irradiated with the conventional technique using an anterior field. IMRT technique was carried out using an inverse planning system. Treatment was done with the Multi-leaf Intensity Modulating Collimator through a slice-by-slice arc rotation approach. During the corresponding period, 65 patients with nasopharyngeal carcinoma were treated by conventional radiotherapy （conventional radiotherapy group）. Acute and late toxicities were graded according to RTOG/EORTC radiation morbidity scoring criteria. Results In the conventional radiotherapy group 1 patient had Ⅲ degree toxicity reaction; 64 patients hadⅠ＋Ⅱ degree toxicity reaction. The IMRT group included 2 cases（3.3%）Ⅲ degree toxicity response and 58 cases ofⅠ＋Ⅱdegree toxicity reaction. The incidence rate of Ⅲ degree toxicity reaction in two groups had significant difference（P〈0.05）. Most of patients had grade 1 to 2 acute and grade 0 to 1 late toxicities. Xerostomia decreased gradually in 37 evaluable patients. Conclusion Intensity modulated radiation therapy can protect the normal tissue in the treatment of NPC.