A segmentation system for segmenting an object in an image, the segmentation system comprising: - an image providing unit for providing an image of an object, the image representing an image volume, - a model providing unit for providing a deformable surface model for being adapted to a surface of the object, wherein the surface model comprises surface elements defining respective parts of a mesh surface, - a subvolumes determination unit for placing the surface model within the image and for determining for each surface element of the surface model a respective subvolume of the image such that the respective subvolume overlaps with the respective surface element, - a neural network providing unit for providing a convolutional neural network being adapted to determine distances (d) between surface elements of the surface model and a boundary of the object in the image based on determined subvolumes, wherein the neural network providing unit is adapted to provide a further convolutional neural network being adapted to determine confidence values for surface elements of the surface model based on the subvolumes, wherein a confidence value for a respective surface element is indicative of an estimation of a deviation of the distance determined for the respective surface element from the actual distance of the respective surface element to the boundary of the object in the image, wherein the segmentation system further comprises a confidence value determination unit for determining confidence values for the surface elements of the surface model by using the provided further neural network based on the determined subvolumes, - a distance determination unit for determining respective distances (d) between the surface elements of the provided and placed surface model and the boundary of the object in the provided image by using the provided neural network based on the determined subvolumes, and - a model adaptation unit for adapting the surface model to the object in the image in accordance with the determined distances (d), wherein the model adaptation unit is adapted to adapt the surface model in accordance with the determined distances (d) and based on the respective confidence value determined for the respective surface element. - an image providing unit for providing an image of an object, the image representing an image volume, - a model providing unit for providing a deformable surface model for being adapted to a surface of the object, wherein the surface model comprises surface elements defining respective parts of a mesh surface, - a subvolumes determination unit for placing the surface model within the image and for determining for each surface element of the surface model a respective subvolume of the image such that the respective subvolume overlaps with the respective surface element, - a neural network providing unit for providing a convolutional neural network being adapted to determine distances (d) between surface elements of the surface model and a boundary of the object in the image based on determined subvolumes, wherein the neural network providing unit is adapted to provide a further convolutional neural network being adapted to determine confidence values for surface elements of the surface model based on the subvolumes, wherein a confidence value for a respective surface element is indicative of an estimation of a deviation of the distance determined for the respective surface element from the actual distance of the respective surface element to the boundary of the object in the image, wherein the segmentation system further comprises a confidence value determination unit for determining confidence values for the surface elements of the surface model by using the provided further neural network based on the determined subvolumes, - a distance determination unit for determining respective distances (d) between the surface elements of the provided and placed surface model and the boundary of the object in the provided image by using the provided neural network based on the determined subvolumes, and - a model adaptation unit for adapting the surface model to the object in the image in accordance with the determined distances (d), wherein the model adaptation unit is adapted to adapt the surface model in accordance with the determined distances (d) and based on the respective confidence value determined for the respective surface element.