In one embodiment, radiotherapy treatment is provided to a target volume of a patient by configuring a multileaf collimator of a radiation treatment machine in a first orientation so as to form an actual aperture having a first orientation, delivering radiation to the target volume through the actual aperture while in the first orientation with a single pass along an arcuate path centered on the target volume, configuring the multileaf collimator in a second orientation so as to place the actual aperture in a second orientation that is different from the first orientation, and delivering radiation to the target volume through the actual aperture while in the second orientation with a single pass back along the arcuate path such that a relatively large cumulative dose of radiation is delivered to the target volume through a virtual aperture created by an area of overlap between the first and second actual aperture orientations.
