1. A non-transitory computer-readable storage medium storing computer executable instructions that when executed by a computer cause the computer to perform a method associated with evaluating global deformations and local deformations in a prostate due to effects of External Beam Radiation Treatment (EBRT), the method comprising: accessing a three dimensional (3D) pre-EBRT magnetic resonance (MR) image of a prostate, where the 3D pre-EBRT image comprises a first set of voxels and first image texture information about the first set of voxels; accessing a 3D post-EBRT MR image of the prostate, where the 3D post-EBRT image comprises a second set of voxels and second image texture information about the second set of voxels; extracting the first image texture information from the 3D pre-EBRT image and extracting the second image texture information from the 3D post-EBRT image; constructing a finite element model (FEM) of the 3D pre-EBRT image, where the FEM discretizes structures of the prostate into elements of the FEM, where the elements of the FEM represent a geometric shape, where the elements of the FEM contain physical properties including elasticity or compressibility, and where the elements of the FEM are connected at nodes of the FEM; producing a deformation of the FEM by applying a series of non-zero external forces to the surface of the prostate represented by the FEM; calculating a transformation of the FEM, based at least in part, on the deformation, where the transformation is parameterized based on the series of non-zero external forces applied to the surface of the prostate; producing a deformed first image texture by deforming, as a function of the deformation of the FEM, the first image texture; determining, as a function of the transformation, a non-zero external force that maximizes an image texture similarity between the deformed first image texture and the second image texture; and upon determining the non-zero external force that maximizes the image texture similarity between the deformed first image texture and the second image texture, registering the 3D pre-EBRT image to the 3D post-EBRT image based, at least in part, on the transformation, where registering the 3D pre-EBRT image to the 3D post-EBRT image comprises spatially aligning the 3D pre-EBRT image with the 3D post-EBRT image.