摘要
目的大部分的胸部肿瘤进行调强放射治疗(intensity modulated radiation therapy,IMRT)时,在计划中加入适当的正向射野都可以有效降低肺脏的低剂量照射体积。本研究旨在探索颈及胸上段食管癌的调强计划中加入正向射野对最终结果的影响。方法选取2015-12-01-2016-02-29吉林省肿瘤医院放疗科接受治疗的颈及胸上段食管癌患者10例,每例患者分别设计一个添加了正向射野的调强计划,即混合调强(H-IMRT)。该计划设计方法如下:利用前后对穿的正向适形野照射胸段靶区,并控制脊髓剂量<40Gy,之后添加7个射野方向均分的调强野,选取调强野中对肺脏保护不利的射野方向,使其仅照射锁骨上段靶区,最后优化调强野直至剂量分布达到临床应用要求。对H-IMRT和传统IMRT做比较研究。分析H-IMRT的剂量学优势及治疗特性。结果 H-IMRT靶区的适形度指数(Z=-2.096,P=0.042)和均匀性指数(Z=-2.075,P=0.046)都明显优于IMRT计划。H-IMRT肺脏的V5、V10、V15分别比IMRT计划低约15.5%(Z=-2.865,P=0.012)、22.3%(Z=-2.873,P=0.005)、30.3%(Z=-2.932,P=0.003);V20、V25、V30分别比IMRT计划低约31.7%(Z=-2.916,P=0.002)、24.8%(Z=-2.743,P=0.008)和15.5%(Z=-1.776,P=0.026);且H-IMRT肺的平均剂量也要比IMRT计划低约16.4%(Z=-2.653,P=0.005)。但H-IMRT的MUs数比IMRT计划多约18.9%,差异有统计学意义,Z=-2.847,P=0.005。结论利用IMRT技术治疗颈及胸上段食管癌时,在计划中加入合适的正向射野,可以让计划表现出更加优秀的剂量调制能力,在靶区覆盖和肺脏保护两方面都展现出明显的剂量学优势。
OBJECTIVE Adding positive field to the plan can effectively reduce the lung volume irradiated by low dose, whenduring the treatment of most of the thoracic targets with intensity modulated radiation therapy（IMRT）. This article is intended to investigate the potential benefits of positive fields combined with IMRT fields in the treatment of cer- vical and upper esophageal carcinoma. METHODS The following two plan techniques were compared for 10 cervical and upper esophageal carcinoma patients using dose-volume histogram analysis： hybrid plan and conventional IMRT. The hy- brid technique design method was as follows： The thoracic target volume was irradiated by the static fields that was op- posed anteroposterior, and Spinal spinal cord dose was limited to less than 40 Gy. After that, to add the IMRT beams u- sing sever equally spaced eoplanar beams, limiting Irradiation range of IMRT beams which were the most detrimental to sparing of lung, so that it only irradiated the target volume of supraclavicular, and the other IMRT beams irradiated the whole target volume. RESULTS Hybird plan provided a better conformity index （Z=-2. 096,P=0. 042） and homoge neity indices （Z----2. 075,P=0. 046） than IMRT did. Vs ,V10 and Vl of lung in hybrid plan were reduced by 15.5% （Z=--2.865,P：0.012）,22.3%0（Z=-2. 873,P〈0. 005） and 30.3%（Z：--2.932,P=0.003）,respectively. V20, V25 and V3o of lung in hybrid plan were reduced by 31.70% （Z= 2. 916, P 0. 002）, 24.8% （Z-- --2. 743, P： 0. 008）and 15. 5;（Z= --1. 776;P--0. 026）, respectively. Compared to IMRT, Hybrid plan increased MUs by 18. 9%（Z= --2. 847,P： 0. 005）. CONCLUSION For radiation therapy of cervical and upper esophageal carcinoma, the hybridtechnique shows a better dose modulation ability,and provides better target dose conformal and uniformity, and sparing of lung than IMRT.
出处
《中华肿瘤防治杂志》
CAS
北大核心
2017年第18期1301-1304,共4页
Chinese Journal of Cancer Prevention and Treatment
关键词
调强放疗
颈及胸上段食管癌
正向射野
混合调强
intensity-modulated radiation therapy
cervical and upper esophageal carcinoma
positive fields
Hybrid IMRT
