摘要
目的:探讨Monaco计划系统中计算网格对头颈部肿瘤小体积危及器官剂量学影响。方法:选取10例头颈部NKT(结外NK/T细胞淋巴瘤)患者,Monaco计划系统按不同计算网格分A、B两组制作计划。A组以3mm网格优化,以1、2、4、5mm网格重新计算剂量生成新计划;B组按1、2、3、4、5mm网格直接优化计划。A、B两组计划其它参数均保持不变,归一到处方剂量包绕95%靶区体积。统计晶体及计划敏感器官体积(PRV)、视交叉和视神经最大、最小和平均剂量、靶区CI和HI,剂量重新计算与优化时间。以1mm网格数据为参考,采用配对t检验对上述结果进行统计分析。结果:2mm与1mm网格配对t检验A组右晶体PRV、右视神经和视交叉有统计学差异(P<0.05),B组右晶体PRV和视交叉有统计学差异,其它危及器官(OAR)均无统计学差异(P>0.05)。3mm与1mm网格配对t检验所有OAR均无统计学差异。4mm与1mm网格配对t检验A、B两组晶体及PRV除B组右晶体PRV外均有统计学差异,而视神经和视交叉均无统计学差异。5mm与1mm网格配对t检验A、B两组晶体及PRV均有统计学差异,视神经和视交叉除A组视交叉外均无统计学差异。1mm网格A、B两组OAR的剂量学参数、靶区的CI和HI没有统计学差异,B组计划所需时间是A组的4倍。结论:较之于视神经和视交叉,晶体及PRV对计算网格变化更敏感。Monaco计划系统兼顾计算精度和工作效率,头颈部肿瘤采用3mm计算网格是合适的选择。当临床需要1mm网格数据时,可采用3mm网格优化并重新计算到1mm网格剂量的方法。
Objective To investigate the dosimetric effects of computational grid size in Monaco treatment planning system on the small organs-at-risk (OAR) in patients with head and neck cacer. Methods Ten patients with head and neck NKT (extranodal NK/T-cell lymphoma) were enrolled in the study, and two groups (groups A and B) of radiotherapy plan with different grid sizes were designed by Monaco treatment planning system. The plans in group Awere optimized with 3 mm grid, and then 4 new plans were obtained by recalculating the final dose with the grid of 1, 2, 4 and 5 mm;in group B, 5 plans were generated with different grids (1, 2, 3, 4 and 5 mm). The other parameters in groups Aand B remain unchanged, and the dose distribution was normalized to a prescription dose of 95% of planning target volume. The maximum, minimum and mean doses of lens, planning organ at risk volume (PRV) of lens, optic chiasm and optic nerve, the homogeneity index and conformity index of target areas, the time for dose recalculation and optimization were analyzed. Paired t test was used to analyze the obtained results, using 1 mm grid data as the reference. Results The paired t test on 2 mm grid and 1 mm grid showed that there was no statistical differences in OAR (P>0.05), except for PRV of the right lens, the right optic nerve and optic chiasm in group A (P<0.05) as well as the PRV of the right lens and optic chiasm in group B (P<0.05). No significant difference was found in OAR between 3 mm grid and 1 mm grid. There were statistical differences in groups A and B between 4 mm grid and 1 mm grid, except for the optic nerve and optic chiasm in groups Aand B, and PRV of the right lens in group B. The paired t test on 5 mm grid and 1 mm grid showed that there were statistical differences in lens and lens PRV in groups A and B, and optic chiasm in group A, not in the optic nerve in groups A and B and optic chiasm in group B. There was no statistical difference in the dose parameters of OAR, and the CI and HI of target areas between group A (1 mm grid
作者
裴运通
胡金炎
马阳光
王海洋
刘乐乐
姬腾飞
郭跃信
PEI Yuntong;HU Jinyan;MA Yangguang;WANG Haiyang;LIU Lele;JI Tengfei;GUO Yuexin(Department of Radiation Oncology,the First Affiliated Hospital of Zhengzhou University,Zhengzhou 453003,China)
出处
《中国医学物理学杂志》
CSCD
2019年第10期1145-1151,共7页
Chinese Journal of Medical Physics
基金
河南省医学科技攻关计划(201602035)
河南省科技厅科技攻关计划(182102310369)
