摘要目的 比较两种自动勾画软件(Smart Segmentation与MIM Atlas)勾画鼻咽癌危及器官(OAR)的准确性.方法 回顾性选取2015—2016年浙江大学医学院附属第一医院收治的鼻咽癌患者共55例,在CT图像上手动勾画OAR,以简单随机抽样方式取其中30例在Smart Segmentation与MIM Atlas中创建各自的病例库,剩余25例作为测试病例在两个软件中运行得到两组自动勾画结果 .以手动勾画为金标准,计算两组自动勾画结果的戴斯相似性系数(DSC)、 豪斯多夫距离(HD)、绝对体积差(△V),通过比较以上3个参数来评估两种软件勾画鼻咽癌危及器官的准确性.结果Smart Segmentation与MIM Atlas勾画所有器官的总体DSC分别为(0.79±0.13)和(0.62±0.24)(t=14.06,P<0.05);总体HD分别为(5.50±3.84)和(8.38±4.88)mm(t=-11.40,P<0.05);总体△V为(1.52±2.46)、(2.38±3.57)cm3(t=-4.70,P<0.05).MIM Atlas勾画的11个器官(脑干、视交叉、左右眼晶状体、 左右视神经、 左右眼球、 左右侧腮腺、 脊髓)的DSC均值大于Smart Segmentation的结果(t=5.27、4.41、6.34、5.70、10.62、7.45、3.96、4.26、6.25、5.42、7.23,P<0.05).MIM Atlas勾画的10个器官(脑干、 视交叉、 左右眼晶状体、 左右视神经、 左右眼球、左侧腮腺、脊髓)的HD均值小于Smart Segmentation(t=-4.51、-4.49、-3.92、-3.45、-5.36、-5.56、-3.89、-3.90、-3.60、-3.68,P<0.05).MIM Atlas勾画的6个器官(脑干、 视交叉、 左眼晶状体、 左右视神经、 右眼球)的△V均值小于Smart Segmentation(t=-2.83、-3.39、-2.56、-2.27、-2.43、-2.51,P<0.05).结论 对于体积较大的器官,两种软件都有较好的勾画结果.器官的体积越小、 边界越模糊,则勾画结果越差.MIM Atlas的勾画结果总体上优于Smart Segmentation.

abstractsObjective To compare the accuracy of two automatic segmentation softwares ( Smart Segmentation and MIM Atlas) in organs at risk ( OARs) contouring for nasopharyngeal carcinoma ( NPC) . Methods Totally 55 NPC patients were retrospectively reviewed with manually contoured OARs on CT images, in which 30 cases were randomly selected to create a data base in the Smart Segmentation and MIM Atlas. The remaining 25 cases were automatically contoured with Smart Segmentation and MIM as test cases. The automatic contouring accuracies of two softwares were evaluated with Dice coefficient( DSC) , Hausdorff distance( HD) , and absolute volume difference(△V) using manual contours as a golden standard. Results The overall DSC, HD and △V of all organs contoured by MIM Atlas and Smart Segmentation were (0.79±0.13) vs. (0.62±0.24) (t= 14.06, P<0.05),(5.50±3.84)mm vs.(8.38±4.88)mm ( t=-11. 40, P<0. 05 ) , and ( 1. 52 ± 2. 46 ) cm3 vs. ( 2. 38 ± 3. 57 ) cm3 ( t = -4. 70, P<0. 05 ) , respectively. The average DSC of 11 organs ( brain stem, optic chiasm, bilateral lens, bilateral optic nerve, bilateral eyeballs, bilateral parotid gland, spinal cord) delineated by MIM Atlas was statistically greater than that of Smart Segmentation ( t=5. 27, 4. 41, 6. 34, 5. 70, 10. 62, 7. 45, 3. 96, 4. 26, 6. 25, 5. 42, 7. 23, P<0. 05) . The average HD of 10 organs ( brain stem, optic chiasm, bilateral lens, bilateral optic nerve, bilateral eyeballs, left parotid gland, spinal cord) delineated by MIM Atlas was statistically less than that of Smart Segmentation ( t=-4. 51, -4. 49, -3. 92, -3. 45, -5. 36, -5. 56, -3. 89, -3. 90,-3. 60, -3. 68, P<0. 05). The average △V of 6 organs (brain stem, optic chiasm, left len, bilateral optic nerve, right eyeball) delineated by MIM Atlas was statistically less than that of Smart Segmentation ( t=-2. 83, -3. 39, -2. 56, -2. 27, -2. 43, -2. 51, P<0. 05 ) . Conclusions Both softwares have reasonable contouring accuracy for larger organs. The accuracy decreased with the decrease of organ volumes and blurred boundary. Generally, MIM Atlas's performs better than Smart Segmentation does.