Propagation of target and organ at risk contours in radiotherapy of prostate cancer using deformable image registration
Propagation of target and organ at risk contours in radiotherapy of prostate cancer using deformable image registration
复制标题
DOI：
10.3109/0284186x.2010.503662
复制
发表时间：
2010-10-01
期刊：
影响因子：
3.1
通讯作者：
Muren, Ludvig Paul
中科院分区：
文献类型：
--
作者：
Thornqvist, Sara;Petersen, Jorgen B. B.;Muren, Ludvig Paul
背景成功的形变图像配准是放射治疗中剂量累积和计划自适应的重要组成部分。本研究的目的是评价可变形图像配准应用程序的性能，用于使用骨盆的重复CT扫描传播轮廓，骨盆是一个预计会发生相当大变形的区域。材料和方法。该研究涉及4名前列腺癌患者，每人进行9-11次重复CT扫描。肿瘤学家在所有CT扫描中勾画膀胱、直肠、盆腔淋巴结（CTV-ln）和前列腺（CTV-p）的临床靶体积。使用最近发布的商业临床软件应用程序，通过刚性和变形配准，将参考CT回顾性配准到重复CT扫描。应用了两种不同的基于扩散的“恶魔”可变形配准算法，其允许的变形量不同，其中算法A比算法B更慷慨。传播结构的评价包括定量测量和定性评分。结果我们发现算法之间的差异对于膀胱和直肠最为明显。对于膀胱和直肠，算法A获得的平均Dice相似系数相对于刚性配准增加了12%和13%，而算法B为2%。对于膀胱，算法A的平均灵敏度和阳性预测值分别为0.92和0.87，算法B的平均灵敏度和阳性预测值分别为0.82和0.83。算法A的直肠相应值为0.81和0.76，算法B的相应值为0.75和0.69。这意味着算法A分别有57%和26%通过了膀胱和直肠的临床评价，而算法B分别为17%和14%。对于CTV-ln和CTV-p，这两种算法在所有测量中表现良好，e. G. 86%的靶结构通过了临床评价。结论.可变形的图像配准改善了轮廓传播在骨盆的所有器官的调查。观察到算法性能的差异，这对于膀胱和直肠的高度可变形器官变得更加明显。
Background. Successful deformable image registration is an essential component of both dose accumulation and plan adaptation in radiotherapy. The aim of this study was to evaluate the performance of a deformable image registration application for propagation of contours using repeat CT scans of the pelvis, a region where considerable deformations are expected. Material and methods. The study involved four prostate cancer patients, each with 9-11 repeat CT scans. An oncologist contoured bladder, rectum, clinical target volume of pelvic lymph nodes (CTV-ln) and prostate (CTV-p) in all CT scans. The reference CT was retrospectively registered to the repeat CT scans with both rigid and deformable registration using a recently released commercial clinical software application. Two different diffusion-based 'demons' deformable registration algorithms were applied, differing in the amount of deformations being allowed, with algorithm A being more generous than algorithm B. The evaluation of the propagated structures included both quantitative measures and qualitative scoring. Results. We found the differences between the algorithms to be most evident for bladder and rectum. An increase in mean Dice similarity coefficient relative the rigid registrations of 12% and 13% was obtained with algorithm A for bladder and rectum, compared to 2% with algorithm B. For bladder the mean sensitivity and positive predictive value was 0.92 and 0.87 with algorithm A and 0.82 and 0.83 with algorithm B. Corresponding values for rectum was 0.81 and 0.76 with algorithm A and 0.75 and 0.69 with algorithm B. This translated into 57% and 26% passing the clinical evaluation for bladder and rectum, with algorithm A, compared to 17% and 14% with algorithm B. For CTV-ln and CTV-p both algorithms performed well by all measures, e. g. with 86% of the target structures passing the clinical evaluation. Conclusions. Deformable image registration improved contour propagation in the pelvis for all organs investigated. Differences in the performance of the algorithms were seen which became more pronounced for the highly deformable organs of bladder and rectum.