1. A method for programming operation of a radiation therapy system to deliver radiation therapy to a subject, the method comprising: acquiring medical images of the subject including functional information and anatomical information about the subject; generating texture feature images using the acquired medical images; using the medical images and the texture feature images, determining a plurality of segmentation surfaces by minimizing a relationship between a region growing algorithm that selects a region of interest (ROI) to determine a given segmentation surface and cost function for evaluating the given segmentation surface; synthesizing the plurality of segmentation surfaces into a segmentation report; and using information from the segmentation report to program operation of the radiation therapy system for a delivery of radiation therapy to the subject.