1. A method for locating a target in a three-dimensional (3D) volume, the method comprising: storing in memory a 3D medical image containing a region of interest associated with the target; extracting, using a processor, a two-dimensional (2D) slice from the stored 3D medical image containing the region of interest associated with the target; determining a 2D patch for the 2D slice, wherein the 2D patch corresponds to an area of the 2D slice associated with the region of interest; determining, for the 2D patch, offset information, the offset information including a distance between a location of the 2D patch and a reference point in the 3D volume; and locating, using the processor, the target in the 3D volume based on the 2D patch and the offset information.