VIRTUAL PORTAL IMAGE FOR TREATMENT SETUP IN A RADIATION THERAPY SYSTEM

A computer-implemented method of performing radiation therapy on a target volume within an anatomical region of a patient includes: acquiring a cone-beam computed tomography (CBCT) image of the region while the region is positioned in a first preliminary treatment location; reconstructing a current digital volume of the region based on the CBCT image of the region; generating a first beam's-eye-view of the region based on the current digital volume and an offset between the first preliminary treatment location and a reference treatment location; modifying the first beam's-eye-view of the region with one or more visual cues associated with a treatment field for the target volume; and displaying the first beam's-eye-view with the one or more visual cues.