A computer-readable medium comprising computer-readable instructions for adjusting radiotherapy treatment for a patient in real time, the computer-readable instructions comprising instructions for performing operations comprising: retrieving a reference plan that includes three-dimensional volume representation of information for the patient and a plurality of radiotherapy beam delivery segments; identifying a first portion of the 3D volume representation of information for a first beam delivery segment of the plurality of radiotherapy beam delivery segments that includes a volumetric portion of a target irradiated by the first beam delivery segment; accessing a deformation model representing patient deformation during a radiotherapy treatment fraction; deforming the first portion of the 3D volume representation of information based on the deformation model; and updating one or more parameters of a radiotherapy treatment device based on the deformed first portion of the 3D volume representation of information; wherein the volumetric portion in the first portion includes a part of the target to be irradiated and an organ-at-risk, and wherein the method further comprises: identifying a first set of voxels in the first portion that corresponds to the target to be irradiated; identifying a second set of voxels in the first portion that corresponds to the organ-at risk; deforming the first set of voxels separately from deforming the second set of voxels based on the deformation model; and changing a shape of the beam delivered during the first radiotherapy beam delivery segment based on the deformed first and second sets of voxels. retrieving a reference plan that includes three-dimensional volume representation of information for the patient and a plurality of radiotherapy beam delivery segments; identifying a first portion of the 3D volume representation of information for a first beam delivery segment of the plurality of radiotherapy beam delivery segments that includes a volumetric portion of a target irradiated by the first beam delivery segment; accessing a deformation model representing patient deformation during a radiotherapy treatment fraction; deforming the first portion of the 3D volume representation of information based on the deformation model; and updating one or more parameters of a radiotherapy treatment device based on the deformed first portion of the 3D volume representation of information; wherein the volumetric portion in the first portion includes a part of the target to be irradiated and an organ-at-risk, and wherein the method further comprises: identifying a first set of voxels in the first portion that corresponds to the target to be irradiated; identifying a second set of voxels in the first portion that corresponds to the organ-at risk; deforming the first set of voxels separately from deforming the second set of voxels based on the deformation model; and changing a shape of the beam delivered during the first radiotherapy beam delivery segment based on the deformed first and second sets of voxels. identifying a first set of voxels in the first portion that corresponds to the target to be irradiated; identifying a second set of voxels in the first portion that corresponds to the organ-at risk; deforming the first set of voxels separately from deforming the second set of voxels based on the deformation model; and changing a shape of the beam delivered during the first radiotherapy beam delivery segment based on the deformed first and second sets of voxels.