调强适形放射治疗对局部晚期鼻咽癌的临床疗效  

Intensity Modulated Radiotherapy for Local-regional Advanced Nasopharyngeal Carcinoma

作　　者：赵充[1] 韩非[1] 卢丽霞[1] 黄劭敏[1] 林承光[1] 邓小武[1] 卢泰祥[1] 崔念基[1] 

机构地区：[1]中山大学肿瘤防治中心放疗科,广东广州510060

出　　处：《癌症》2004年第z1期1532-1537,共6页Chinese Journal of Cancer

基　　金：广东省医学科学研究基金(No.A2001219)~~

摘　　要：背景及目的:局部和区域未控是局部晚期鼻咽癌放疗失败的主要原因之一。临床研究表明,鼻咽癌的局部控制率与靶体积的照射剂量呈正相关。由于鼻咽解剖位置的特殊性,采用常规二维放疗方法提高靶体积的照射剂量受到周围敏感器官耐受剂量的限制。本研究将三维调强适形放射治疗(intensitymodulatedradiationtherapy,IMRT)技术应用于局部晚期鼻咽癌的治疗,以期通过安全地增加靶体积照射剂量,达到提高局部和区域控制率的目的。方法:共60例初治原发鼻咽癌患者进入本研究。其中Ⅲ期49例,Ⅳa期11例。全部患者均使用IMRT技术行单纯根治性放疗,放疗计划及实施由NOMOS公司PEACOCK系统完成。采用连续加速推量(SMARTBoost)方法照射,处方剂量:鼻咽大体肿瘤体积(GTVnx)30次共68Gy,颈部转移淋巴结(GTVnd)30次共60～64Gy,临床靶体积Ⅰ(TargetⅠ)30次共60Gy,临床靶体积Ⅱ(TargetⅡ)30次共54Gy。利用剂量体积直方图评价靶体积和敏感器官的受照剂量,用RTOG/EORTC标准评价急性治疗毒性,采用Kaplan-Meier法计算局部区域控制率、无远处转移率和总生存率。结果:GTVnx、GTVnd(左)、GTVnd(右)、TargetⅠ和TargetⅡ的平均剂量均数分别为71.21、65.85、66.26、67.59和61.42Gy,其中GTVnx、GTVnd(左)和GTVnd(右)的平均分次剂量分别达2.37?BACKGROUND &OBJECTIVE: Local-regional uncontrolled is an import an t reason of treatment failure for advanced nasopharyngeal carcinoma (NPC) after radiotherapy. Local-regional control rate increased with dose to tumor target v olumes. Because of the complex anatomy features, dose escalation using conventio nal two-dimensional radiotherapy planning is limited by the tolerance of adjace nt critical organs. In order to enhance doses to target volumes and local-regio nal control rates, this study explored application of intensity modulated radiat ion therapy (IMRT) in local-regional advanced NPC. METHODS: Sixty patients with naive primary NPC, 49 in stage Ⅲ, and 11 in stage Ⅳa, received IMRT alone wit h an inverse planning system (CORVUS 3.0, Peacock plan). Treatment was delivered with the Multi-leaf Intensity Modulating Collimator (MIMiC) using a slice-by-slice arc rotation approach. The prescription dose was 68 Gy to nasopharynx gr oss tumor volume (GTVnx), 60-64 Gy to positive neck lymph nodes (GTVnd), 60 Gy to clinical target volume Ⅰ(Target Ⅰ), and 54 Gy to clinical target volume Ⅱ( Target Ⅱ), delivered by 30 fractions. Acute normal tissue effects were graded a ccording to RTOG/EORTC radiation morbidity scoring criteria. Local control rate, regional control rate, distant metastasis-free rate, and overall survival rate were calculated using Kaplan-Meier method. RESULTS: Analysis of dose-volume h istograms (DVH) showed that the average mean dose delivered were 71.21 Gy to GTV nx, 65.85 Gy to GTVnd(L), 66.26 Gy to GTVnd(R), 67.59 Gy to Target Ⅰ, and 61.42 Gy to Target Ⅱ. The mean fractional dosage delivered were 2.37 Gy to GTVnx, 2. 20 Gy to GTVnd(L), and 2.21 Gy to GTVnd(R). The average volumes of all target vo lumes covered by 95%isodose were more than 99%, and the average volume of GTVn x covered by 105%isodose was 43.87%; 5%of brainstem volume, and 1cc of spinal cord volume received average dosage were 46.96 Gy, and 39.99 Gy; 33%of volume of bilateral parotids, and T-M Joints received average do

关 键 词：鼻咽肿瘤 靶体积 调强适形 放疗 局部控制 

分 类 号：R739.63[医药卫生—肿瘤]