呼吸运动对两种子野分割算法剂量影响研究  

Experimental study on the effect of respiratory movement on dose of the two sub-field division algorithm

作　　者：刘苓苓[1] 费振乐[1,2] 王宏志[1] 崔相利[1] 单超[1] 

机构地区：[1]中国科学院合肥物质科学研究院医学物理与技术中心.中国科学院合肥肿瘤医院放疗中心,安徽合肥230031 [2]中国解放军第一零五医院肿瘤诊疗中心,安徽合肥230031

出　　处：《中华肿瘤防治杂志》2017年第9期626-629,共4页Chinese Journal of Cancer Prevention and Treatment

基　　金：中国科学院合肥物质科学研究院院长基金(YZJJ201325)

摘　　要：目的呼吸运动影响患者实际照射剂量,不同多页光栅(multi-leaf collimator,MLC)的运动方式对呼吸运动造成剂量偏差的敏感性不同。本研究旨在定量分析两种子野分割算法受呼吸幅度影响的剂量偏差大小。方法收集2013-06-10-2015-04-15中国科学院合肥肿瘤医院收治的肺癌患者10例,两种类型放疗计划各制定10例。呼吸运动仪带动QA模体正弦运动模拟患者头脚方向不同呼吸幅度的呼吸运动,分别采集等中心层面剂量。通过Verisoft分析采集数据的射野通过率和剂量分布。结果 10例肺癌患者Slidingwnd和Smartsequence子野分割方式产生的子野数分别为40±5.2和20±7.7,P=0.007;机器跳数分别为(388±56.6)和(346±60.4)MU,P=0.007。随着呼吸幅度的增加,射野通过率变小。Smartsequence和Slidingwnd在8 mm幅度时射野通过率分别为(85.27±4.57)%和(87.26±5.25)%,t=3.435,P=0.007;在10mm幅度时射野通过率分别为(74.95±5.98)%和(79.13±5.11)%,t=6.05,P<0.001。Smartsequence比Slidingwnd射野通过率低,且通过率<90%;呼吸幅度=6mm时,两种计划通过率为(91.81±3.65)%和(92.67±4.55)%,差异无统计学意义,P>0.05。呼吸幅度<6mm时,两种计划通过率差异无统计学意义,P>0.05;通过率>90%,满足临床剂量验证要求。结论 Smartsequence子野分割算法对呼吸运动造成的剂量偏差敏感性大,建议选择Slidingwnd子野分割方式。OBJECTIVE Respiratory movement affects the patient＇s actual exposure dose,different MLC moving modes have different sensitivities to the dose deviation of respiration.The objective of ours study is to quantitative investigate the effect of respiratory movement on the dose of two sub-field division algorithm.METHODS The study involved10 lung cancer patients treated in Cancer Hospital of Hefei Institutes of Physical Science of Chinese Academy of Sciences from June 10,2013 to April 15,2015,10 cases were established for two types of Radiation Therapy respectively.Respiratory movement instrument driven a QA model to simulate respiratory movement in the direction of human head and foot to collect dose distribution in isocenter with different amplitudes of respiratory movement.By Verisoft software,we analyzed beam passing rates and dose distribution.RESULTS The segments（20±7.7）and MUs（346±60.4）of Smartsequence were less than those of Slidingwnd（40±5.2,388±56.6）.Respiratory movement primarily made the dose outside of the marginal target in the movement direction higher in both intensity modulated radiotherapy.As the respiratory amplitude increased,the beam passing rate was lower.The beam passing rates of Smartsequence and Slidingwnd were（85.27±4.57）%,（87.26±5.25）% and（74.95±5.98）%,（79.13±5.11）%,respectively at 8mm and 10 mm amplitude,the difference was significant（t were 3.435 and 6.05,P were 0.007 and 0.001）.Beam passing rate of Sartsequence was smaller than that of Slidingwnd,and the beam passing rate was lower than 90%.There was no significant when the respiratory amplitude was 6mm（P〈0.05）,and the beam passing rate were（91.81±3.65）%,（92.67±4.55）%.There was no significant when the respiratory amplitude was lower than 6mm（P〈0.05）,and the beam passing rate was larger than 90%.CONCLUSION Smartsequence segmentation algorithm is more sensitivity for respiratory movement caused by dose deviation,it is recommended to choose Slidingwnd subdivision method.

关 键 词：呼吸运动幅度 Smartsequence Slidingwnd 剂量分布 射野通过率 

分 类 号：R730.55[医药卫生—肿瘤] R734.2[医药卫生—临床医学]