摘要
目的:当靶区尺寸较大,超过瓦里安加速器MLC开放最大限度时,静态调强的射野会分自动为两个或更多的分野。本研究采用固定铅门技术,减少总的射野数。方法:选取10例鼻咽癌患者分别制定分野技术计划和固定铅门技术计划,评价并对比两种计划靶区及危及器官的剂量学参数、机器跳数(MUs)和治疗时间(T)。结果:两种计划都能满足临床剂量要求,靶区的适形指数差异、均匀指数差异、危及器官剂量差异均没有统计学意义(P>0.05)。与分野技术计划相比,固定铅门技术计划的机器跳数平均较少8%,治疗时间平均减少31%(约3.2min),差异具有统计学意义(P<0.05)。结论:对比两种技术的计划。靶区和危及器官的DVH几乎一致,可以显著减少机器跳数和治疗时间,提高工作效率。
Objective： Because some of the target dimensions were larger than the maximum limitation of MLC opening on the Varian machine, the step and shoot IMRT field was divided into two or more subfields. This research aims to use a fixed-jaw technique to reduce the numbers of split fields. Methods： Ten patients with Nasopharynx Carcinoma（NPC） were planned using split-field technique and fixed-jaw technique, respectively. The dosimetric parameters of the targets and OARs were studied and compared with both techniques. The total monitor units （MUs） and the treatment time were also compared. Results： Both plans could satisfy the clinical requirements. There was no statistical significance in the conformity index （CI） and the homo- geneity index （HI） of the targets and the dose delivered to the OARs between both plans. However, the differences in MUs and the treatment time were statistically significant. On average the total MUs were reduced by about 8% and the treatment time was reduced by 31% or about 3.2 min using the fixed-jaw technique. Conclusions： The comparison of fixed-jaw technique and split-field technique plans reveal almost identical DVHs of PTVs and OARs. However, the fixed-jaw technique can reduce the total MUs and the treatment time significantly. It has reduced the workload greatly.
出处
《中国医学物理学杂志》
CSCD
2013年第3期4104-4107,共4页
Chinese Journal of Medical Physics
关键词
大靶区
静态调强
分野
固定铅门
big target
step and shoot IMRT
split-field
fixed-jaw
