直肠癌放疗不同技术和体位对小肠受照剂量的比较  

Influence of modern radiotherapy technique or treatment position on the irradiated volume in small bowel sparing for rectal cancer patients

作　　者：孔伟[1] 夏新舍[1] 折虹[1] 丁喆[1] 闫钢[1] 尚钧[1] 王艳阳[1] 

机构地区：[1]宁夏医科大学总医院肿瘤医院放疗科,宁夏银川750004

出　　处：《现代肿瘤医学》2015年第24期3674-3677,共4页Journal of Modern Oncology

摘　　要：目的：分析直肠癌放射治疗过程中,不同放疗技术和不同治疗体位对小肠受照射体积的影响。方法：选取18例直肠癌患者,膀胱充盈的状态下,治疗体位为仰卧位和俯卧位下分别扫描两组定位CT图像,分别传输至计划系统。在两组CT图像上分别制作三维适形（3D-CRT）和调强放射治疗（IMRT）计划,比较小肠在接受不同剂量的受照绝对体积差异（V5~45）。结果：相同体位,IMRT相比3D-CRT,小肠V45明显降低,V15两者基本接近。采用相同放疗技术,俯卧位相比仰卧位小肠V45和V15均明显降低。结论：直肠癌放射治疗,相比放疗技术,治疗体位对小肠受照体积的影响更大。Objective：To compare the effect of small bowel sparing between modem radiotherapy technique on in- tensity modulated radiotherapy （IMRT） and prone position with belly - board for rectal cancer radiotherapy. Meth- ods ： Eighteen rectal cancer patients underwent two series of CT scans, prone positioned with a belly board and supine positioned with a flat board, both combined using a full bladder protocol. Supine three dimensional conformal radio- therapy（3D- CRT）, supine IMRT and prone 3D -CRT, prone IMRT plans were constructed for each patient. The volume of small bowel receiving doses in 5Gy increments from（5 -45）Gy was calculated using dose- volume histo- grams for each plan. Results：Volumes of small bowel receiving dose in 5Gy increments from（5 -45 ）Cy were calcu- lated,from（35 -45）Gy, there was a significantly lower volume of small bowel treated using the IMRT technique in both supine and prone positions. Compared with supine position, a trend was found for lower volume of irradiated small bowel at each dose level between 5 and 45Gy for prone position,whether using IMRT or not. The differences in small bowel V15 （ the absolute volume of small bowel receiving at least 15Gy） and V45 （ the absolute volume of small bowel receiving at least 45Gy） between supine and prone position were significant. The V45 for the small bowel was signifi- cantly smaller for IMRT than 3D - CRT, but the V45 was approximately equal for IMRT and 3D - CRT. Condusion： Patient position had a greater impact on small bowel sparing than modem radiotherapy technique.

关 键 词：直肠癌 调强放射治疗 治疗体位 小肠受照体积 

分 类 号：R730.55[医药卫生—肿瘤]