不同形变配准对头颈部CT图像的剂量评估研究  

Study on dose evaluation of head and neck CT image with different deformation registration

作　　者：张雪洋 王玉[1] 王明泉[1] 张鹏程[1] 檀桢 ZHANG Xueyang;WANG Yu;WANG Mingquan;ZHANG Pengcheng;TAN Zhen(School of Information and Communication Engineering,North University of China,Taiyuan,Shanxi 030051,China)

机构地区：[1]中北大学信息与通信工程学院,山西太原030051

出　　处：《光电子．激光》2022年第2期157-162,共6页Journal of Optoelectronics·Laser

基　　金：山西省重点研发计划资助项目(201803D121069);山西省应用基础研究项目面上自然基金项目(201801D121162)资助项目。

摘　　要：形变图像配准(deformable image registration,DIR)是自适应放射治疗(adaptive radiotherapy,ART)中轮廓推衍和剂量累积的关键过程。本研究比较3种不同形变配准算法在自适应放疗过程中轮廓推衍和剂量累积的变化。选择头颈部癌症患者的放疗影像数据图像进行这项研究,刚性配准后采用B样条弹性配准和LCC-Demons配准算法,其中B样条弹性算法研究了两种优化指标:归一化互相关、归一化互相关结合弯曲能量惩罚(bending energy penalty,BEP)正则化。剂量评估采用剂量参数D_(95)、D_(min)、D_(mean)、D_(max)和均匀性指数(homogeneity index,HI)来评价累积剂量与初始剂量的差异。几何评估使用Dice相似性系数(Dice similarity coefficient,DSC)和Hausdorff距离(Hausdorff distance,HD)来评价体积之间的重叠度。经过实验,几何评估所得的PTV(planning target volume)靶区、左腮腺、右腮腺Dice系数在B样条弹性配准的两种优化算法和LCC-Demons算法中分别为:0.82±0.07、0.83±0.07、0.86±0.08,其中在LCC-Demons算法下得到的Dice系数达到了最大值0.91,所得的Hausdorff距离均在1—3mm之间,DSC重叠度结果与表明偏差距离均在临床可接受的范围内。对于剂量评估,相应的HI值分别为:1.089、1.082、1.081,LCC-Demons同样达到了最小值1.081,本实验中LCC-Demons在轮廓推衍和剂量映射中均取得了较好的效果,同时也为临床环境下对配准质量的评估提供了一定的借鉴。Deformation image registration(DIR)is a key process of contour derivation and dose accumulation in adaptive radiotherapy(ART).This study compares the changes of contour derivation and dose accumulation in the process of adaptive radiotherapy with three different deformation registration algorithms.The radiotherapy imaging data images of patients with head and neck cancer were selected for this study.After rigid registration,B-spline elastic registration and LCC-Demons registration algorithms were used.The B-spline elastic algorithm studied two optimization indexes:normalization Cross-correlation,normalized cross-correlation combined with bending energy penalty(BEP)regularization.Dose evaluation uses dose parameters D_(95),D_(min),D_(mean),D_(max) and uniformity index(HI)to evaluate the difference between cumulative dose and initial dose.Geometric evaluation uses Dice correlation coefficient(DCS)and Hausdorff distance(HD)to evaluate the degree of overlap between volumes.After experiments,the Dice coefficients of the planning target volume(PTV)target area,left parotid gland and right parotid gland obtained by geometric evaluation are respectively 0.82±0.07,0.83±0.07,0.86±0.08in the two optimization algorithms of B-spline elastic registration and the LCC-Demons algorithm.Among them,the Dice coefficient obtained under the LCC-Demons algorithm reached the maximum value of 0.91,and the obtained Hausdorff distances were all between 1and 3mm.The DSCoverlap result and the indicated deviation distance were both within the clinically acceptable range.For dose evaluation,the corresponding HI values are:1.089,1.082,1.081,LCC-Demons also reached the minimum value of 1.081.Inthisexperiment,LCC-demons achieved good results in contour derivation and dose mapping,and it is also clinical it provides a certain reference for the evaluation of registration quality in the environment.

关 键 词：形变配准 B样条弹性配准 LCC-Demons配准算法 轮廓推衍 剂量累积 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]