“…As such, atlas-based and deep-learning algorithms based on convolutional neural network auto-segmentation have been developed to alleviate the labor-intensive delineation of OARs [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ]. Machine learning approaches, especially deep learning with multi-layered neural networks, have been actively applied to treatment planning in radiotherapy [ 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ]. Many studies have investigated the deep-learning-based auto-segmentation of OARs for various disease sites [ 1 , 2 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ].…”