The plan CT is described to generate dual energy (DRR) that stimulates the treatment time radiographs in order to prospectively evaluate the angles in which issues for the template matching algorithm are present, and thus the visibility of the tumor. The present invention uses template matching to quantify the “trackability” of the target from different angles or directions. The peak-to-side lobe ratio is used to measure trackability. The results of this process influence treatment planning. For example, based on the outcome, either less or no dose is planned for the angles in which the location of the templates cannot be verified and thus, the tumor.
