一种基于实时运动跟踪的自适应dMLC门控放射治疗方法  

Adaptive dMLC gating radiotherapy based on real-time motion tracking

作　　者：周正东[1] 陈元华[1] 余子丽 

机构地区：[1]南京航空航天大学核科学与工程系,南京210016

出　　处：《东南大学学报（自然科学版）》2014年第5期917-923,共7页Journal of Southeast University：Natural Science Edition

摘　　要：提出了一种新颖的自适应动态多叶准直器(dMLC)门控放射治疗方法.通过实时跟踪肿瘤和危及器官(OAR)的运动来控制dMLC叶片的开启与关闭,仅当肿瘤和OAR在射野视观(BEV)内没有重叠时才开启治疗射束进行治疗.4组肿瘤-OAR同步跟踪数据的回顾性仿真实验果表明,肿瘤和OAR的运动模式和相对位置是影响所有指标的最主要因素.在不同的肿瘤-OAR运动模式下,门控治疗占空比高达96.71%,也可能仅有14.12%.增加BEV内的横向距离可提高占空比,并使OAR受照体积减少;增加肿瘤外放边界则具有相反的效果.所提方法具有较好的OAR保护能力,对于占空比较低的情况尤为明显,可以避免高达77.71%的直接照射.A novel adaptive dynamic multi-leaf collimator （dMLC）gating radiotherapy is proposed. The leaf opening/closing of dMLC is controlled by the real-time tracking of the tumor and organ at risk （OAR）.The treatment beam turns on only when there is no overlapping between OAR and tumor in beam’s eye view （BEV）.The experimental results of the retrospective simulations of four synchronous tracking data show that the tumor and OAR motion patterns and their relative positions are the dominant influential factors.For different tumor-OAR motion patterns,the duty cycle can be up to 96.71%and yet may be only 14.12%.The increase of the transverse distance in BEV can improve the duty cycle and reduce the irradiated OAR volume;whereas,the increase of the tumor external boundary exhibits an opposite influence.This proposed technique can provide good OAR protection,especially for cases with low duty cycle,in which as high as 77 .7 1% direct irradiation to OAR can be spared.

关 键 词：放射治疗 呼吸运动 肿瘤运动补偿 自适应dMLC门控 

分 类 号：R318[医药卫生—生物医学工程] TP391[医药卫生—基础医学]