体积对自动勾画软件勾画危及器官准确性的影响

【摘要】目的:评价基于人工智能的自动勾画系统（AccuContour自动勾画软件）对危及器官（OAR）勾画的几何准确性，探讨OAR自动勾画的几何准确性是否受OAR体积的影响。方法:选取161例患者，其中头颈部、胸部、盆腔肿瘤患者各40例，腹部肿瘤患者41例。分别采用AccuContour自动勾画软件和手动勾画的方式对晶体、视神经、眼球、垂体、脑干、腮腺、下颌骨、双肺、心脏、双肾、肝脏、直肠、膀胱、股骨头等部位进行勾画。统计各个勾画部位的戴斯相似系数（DSC）、豪斯多夫距离（HD）、Jaccard系数以及体积这4项参数，并使用DSC、Jaccard系数和HD评价自动勾画的几何准确性。对DSC、HD、Jaccard系数与体积进行Spearman相关性分析，并对晶体、视神经、眼球、腮腺、颞颌关节、双肺、双肾、股骨头等成对部位的DSC、HD、Jaccard系数之间进行Wilcoxon配对秩和检验。结果:各个部位的DSC均数均大于0.7；头颈部的Jaccard系数均数为0.557~0.880，其中最低的为右视神经，最高的为下颌骨。头颈部、胸部、盆腔的HD均数分别小于8、22、16 mm；除肝脏（HD=34.563 mm）外，腹部其他部位的HD均数均小于19 mm。DSCall、Jaccardall系数及HDall的大小与体积具有相关性（rDSC=0.757, PDSC=0.000；rJaccard=0.775, PJaccard=0.000；rHD=0.761, PHD=0.000）。晶体、视神经、眼球、垂体、脑干、腮腺、下颌骨、双肺、膀胱、股骨头等部位的DSC和Jaccard系数与OAR体积具有相关性（P<0.05），HD与体积不具有相关性（P>0.05）。双肺之间的DSC和Jaccard系数差异具有统计学意义（PDSC＝0.000, PJaccard＝0.000）。结论:AccuContour自动勾画软件对于OAR的勾画具有较高的准确性，自动勾画的几何准确性受OAR体积大小的影响。

Effect of volume on the accuracy of organs-at-risk segmentation by automatic segmentation software

Abstract: Objective To evaluate the geometric accuracy of artificial intelligence-based automatic segmentation system (AccuContour automatic segementation software) for the segmentation of organs-at-risk and to investigate whether the geometric accuracy of automatic OAR segmentation is affected by the volume of OAR. Methods A total of 161 patients were enrolled, including 40 cases with tumor in head and neck, chest, and pelvis, and 41 cases with tumor in the abdomen. AccuContour automatic segementation software and manual delineation were used to contour lens, optic nerve, eyeball, pituitary, brainstem, parotid glands, mandible, lungs, heart, kidneys, liver, rectum, bladder, femoral heads and other OAR. The Dice similarity coefficient (DSC), Hausdorff distance (HD), Jaccard coefficient and volume of each segmented OAR were analyzed, and the geometric accuracy of the automatic segmentation was evaluated using DSC, Jaccard coefficient and HD. Spearman correlation analysis was used to verify the correlations between volume and DSC, HD, Jaccard coefficient and Wilcoxon paired rank sum test was conducted on the DSC, HD and Jaccard coefficients of paired OAR such as lens, optic nerves, eyeballs, parotid glands, temporomandibular joints, lungs, kidneys and femoral heads, etc. Results The mean DSC of each OAR was larger than 0.7. The mean Jaccard coefficient of the neck was between 0.557 and 0.880, with the lowest Jaccard coefficient in the right optic nerve and the highest in the mandible. The mean HD of head and neck, chest, and pelvis was less than 8, 22 and 16 mm, respectively. Except for the liver (HD=34.563 mm), the other OAR in the abdomen had a HD less than 19 mm. There were correlations between volume and DSCall, Jaccardall coefficient, HDall (rDSC=0.757, PDSC=0.000 rJaccard=0.775 PJaccard=0.000 rHD=0.761, PHD=0.000). The DSC and Jaccard coefficient of lens, optic nerves, eyeballs, pituitary, brainstem, parotid glands, mandible, lungs, bladder, femoral heads, etc. were also correlated with the volume of OAR (P<0.05), but their HD was not related to volume (P>0.05). The differences in DSC and Jaccard coefficient between bilateral lungs were statistically significant (PDSC =0.000, PJaccard=0.000). Conclusion AccuContour automatic segmentation software has a high accuracy for OAR segmentation, and the geometric accuracy of automatic segmentation is affected by the volume of OAR.