Methods and apparatus for planning imaging include planning imaging in conjunction with planning a radiation treatment. A radiation dose due to planned imaging may be calculated and used in optimizing a plan for delivering therapeutic radiation. Imaging and treatment may be performed using radiation beams having different characteristics. In some embodiments an imaging beam is generated using a low-Z target and a therapy beam is generated using a high-Z target. A radiation treatment planning system may include data characterizing both the imaging beam and the treatment beam.
