头颈部肿瘤HT剂量学研究  

Dosimetric evaluation for head and neck cancer patients treated with helical TomoTherapy

作　　者：张勇乾[1] 张富利[1] 王雅棣[1] 高军茂[1] 许卫东[1] 蒋华勇[1] 姚波[1] 路娜[1] 陈点点[1] 

机构地区：[1]北京军区总医院放疗科,北京100700

出　　处：《中华放射肿瘤学杂志》2014年第6期519-522,共4页Chinese Journal of Radiation Oncology

摘　　要：目的 比较头颈部肿瘤患者HT过程中靶区和OAR计划剂量与实际受量的区别.方法 对12例头颈部肿瘤患者使用HT根治性放疗且每次治疗均行图像引导.选取治疗开始后第2周起每周第1天的图像引导CT图像,在HT的Planned Adaptive模块中重新计算剂量分布,得到当次患者治疗的实际受量.将各CT图像进行形变配准,然后将各单次实际受量叠加得到总实际受量.采用配对t检验或Wilcoxon符号秩检验初始计划剂量与实际受量间差异.结果 总实际受量与初始计划剂量相比GTV的D2、D50相近（P=0.07、0.07）,而D95、D98、D100分别降低2.1％、2.7％、5.6％（P=0.02、0.02、0.02）;PTV的D2相近（P=0.08）,而D50、D95、D98、D100分别降低0.8％、1.9％、3.9％、13.5％（P=0.01、0.00、0.00、0.01）;OAR中脊髓Dmax增加1.2％（P=0.04）.结论 头颈部肿瘤患者HT中最终靶区实际受量比初始计划剂量偏低,而脊髓实际受量比初始计划剂量偏高.对解剖结构变化较大者应适时对靶区及计划进行修改,以达到最佳治疗效果.Objective To compare the differences between planning dose and actual dose of targets and organs at risk （OAR） for head and neck cancer patients with helical tomotherapy （HT）.Methods 12 head and neck patients with HT were enrolled in this study.Prior to each treatment fraction,an MVCT scan was performed.The MVCT images of the first fraction of each week since the second week treatment were chosen,and dose distributions were recalculated on the MVCT images in Planned Adaptive application of HT,which were the actual dose of each fraction.Each single dose distribution and the corresponding CT image were sent to commercial software （MIM5.5）,and deformable image registration was performed to the CT images,and the sum of actual dose was acquired.Dose distribution of targets and OAR of initial treatment plan （Plan-1） and the actual dose distribution （Plan-2） were compared.Results There were no significant differences between Plan-1 and plan-2 for D2,D50 of GTV （P =0.07,0.07） and D2 of PTV （P =0.08）.D95,D98 and D100 of GTV in Plan-2 were lower than in Plan-l,with 2.1％,2.7％ and 5.6％ （P =0.02,0.02,0.02）,respectively.D50,D95,D98 and D100 of PTV in Plan-2 were lower than in Plan-1,with 0.8％,1.9％,3.9％ and 13.5％ （P =0.01,0.00,0.00,0.01）,respectively.Dose of spinal cordwas higher in Plan-2 than in Plan-1,increasing by an Dmax of 1.2％ （P =0.04）.Conclusions In radiotherapy for head and neck cancer actual dose of targets was lower than initial plan dose.Max dose of the spinal cord,however,was higher than in initial plan.For patients who have a significant anatomic change,in order to achieve the best therapeutic effect,modification of targets and treatment plan at the appropriate time is essential.

关 键 词：头颈部肿瘤/螺旋断层疗法 图像引导 形变图像配准 剂量学 

分 类 号：R739.91[医药卫生—肿瘤]