基于IGRT的宫颈癌调强放射治疗摆位误差对剂量学影响的探讨
|
摘要
目的 :利用图像引导调强放射治疗(image guided radiation therapy,IGRT)技术,探讨摆位误差对宫颈癌调强放射治疗剂量学的影响,为下一步确定计划靶区(planning target volume,PTV)合适的外扩边界打下基础。方法:选取采用IGRT技术治疗的宫颈癌患者20例。将20例患者X(左右)、Y(头脚)、Z(腹背)3个方向的平移误差反向输入Pinnacle计划系统,重新计算后评估摆位误差对靶区和危及器官如膀胱、直肠剂量分布的影响。结果:摆位误差使PTV的最小剂量和平均剂量分别减少139.29和48.19 c Gy,表明摆位误差明显降低了95%的PTV体积受照剂量,与原计划相比偏差为5.12%;误差修正之后降低了膀胱和直肠的受量,对小肠受照剂量无明显改变。结论:摆位误差不仅使PTV剂量降低,还增加了危及器官的受照体积,同时影响了靶区的适形度和均匀性。
Objective To investigate the effect of setup error on dosimetry of intensity modulated radiation therapy(IMRT) in the patients with cervical cancer by IGRT technique so as to lay a foundation for determining the appropriate extended boundary of PTV. Methods Twenty patients with cervical cancer were treated with IGRT technology. The X-axis(lateral direction), Y-axis(cranial-caudal) and Z-axis(ventral-dorsal) orientation offset errors of twenty patients were input in the Pinnacle treatment planning system reversely, and the effect of setup errors were evaluated on dose distribution of targets and organs at risk(such as bladder and rectum) after recalculation. Results The setup error reduced the PTV Dminand PTV Dmean by 139.29 and 48.19 c Gy respectively, which indicated that the setup error significantly decreased 95% PTV dose, and had5.12% deviation compared with the original plan. At the same time, the expose doses of the bladder and rectum were lowered after error correction, and there was no obvious change in that of the small intestine. Conclusion The setup error not only reduces the dose in the clinical target volume, but also increases the irradiation volume of the organ at risk and affects the target volume rate and target dose uniformity.
Objective To investigate the effect of setup error on dosimetry of intensity modulated radiation therapy(IMRT) in the patients with cervical cancer by IGRT technique so as to lay a foundation for determining the appropriate extended boundary of PTV. Methods Twenty patients with cervical cancer were treated with IGRT technology. The X-axis(lateral direction), Y-axis(cranial-caudal) and Z-axis(ventral-dorsal) orientation offset errors of twenty patients were input in the Pinnacle treatment planning system reversely, and the effect of setup errors were evaluated on dose distribution of targets and organs at risk(such as bladder and rectum) after recalculation. Results The setup error reduced the PTV Dminand PTV Dmean by 139.29 and 48.19 c Gy respectively, which indicated that the setup error significantly decreased 95% PTV dose, and had5.12% deviation compared with the original plan. At the same time, the expose doses of the bladder and rectum were lowered after error correction, and there was no obvious change in that of the small intestine. Conclusion The setup error not only reduces the dose in the clinical target volume, but also increases the irradiation volume of the organ at risk and affects the target volume rate and target dose uniformity.
引文
[1]徐常冬.宫颈癌调强适形放射治疗的可行性及优势[J].医学理论与实践,2017,30(4):563-564.
[2]胡杰,董晓庆,林清,等.摆位误差对患者剂量学的影响[J].医疗卫生装备,2017,38(7):89-92.
[3]曹倩倩,朱丽红,王俊杰,等.6D治疗床对原发宫颈癌放疗摆位误差及靶区边界的影响[J].中华医学杂志,2015,95(9):689-692.
[4]于娇,陈鑫,赵淑红,等.宫颈癌术后调强放疗摆位误差分析[J].医疗卫生装备,2017,38(1):81-84.
[5]胡逸民.肿瘤放射物理学[M].北京:原子能出版社,2003:328-333.
[6]崔永辉,张淑慧,杨敬贤.应用千伏级锥形束CT分析不同部位肿瘤患者放射治疗的摆位误差[J].中国医药,2017,12(6):909-912.
[7]李列,缪炜烈,刘兴文,等.80例盆腔肿瘤调强放疗摆位误差分析[J].遵义医学院学报,2013,36(2):158-160.
[8]黄丽娜,刘利彬,付万凯.图像引导技术对放疗摆位误差的影响[J].医药前沿,2013(12):382-383.
[9]吴爱东,张绍虎,张红雁,等.锥形束CT测量胸段食管癌调强放疗摆位误差对剂量学的影响[J].中华放射医学与防护杂志,2012,32(4):379-382.
[2]胡杰,董晓庆,林清,等.摆位误差对患者剂量学的影响[J].医疗卫生装备,2017,38(7):89-92.
[3]曹倩倩,朱丽红,王俊杰,等.6D治疗床对原发宫颈癌放疗摆位误差及靶区边界的影响[J].中华医学杂志,2015,95(9):689-692.
[4]于娇,陈鑫,赵淑红,等.宫颈癌术后调强放疗摆位误差分析[J].医疗卫生装备,2017,38(1):81-84.
[5]胡逸民.肿瘤放射物理学[M].北京:原子能出版社,2003:328-333.
[6]崔永辉,张淑慧,杨敬贤.应用千伏级锥形束CT分析不同部位肿瘤患者放射治疗的摆位误差[J].中国医药,2017,12(6):909-912.
[7]李列,缪炜烈,刘兴文,等.80例盆腔肿瘤调强放疗摆位误差分析[J].遵义医学院学报,2013,36(2):158-160.
[8]黄丽娜,刘利彬,付万凯.图像引导技术对放疗摆位误差的影响[J].医药前沿,2013(12):382-383.
[9]吴爱东,张绍虎,张红雁,等.锥形束CT测量胸段食管癌调强放疗摆位误差对剂量学的影响[J].中华放射医学与防护杂志,2012,32(4):379-382.