1. A dose distribution display apparatus comprising: storage circuitry configured to store position information of a support frame which supports an X-ray tube, and X-ray information concerning X-rays generated by the X-ray tube; processing circuitry configured to edit at least one of the X-ray information and the position information in accordance with an operator instruction, and generate a plurality of simulated dose distributions in time series based on the X-ray information and the position information, at least one of which has been edited; and display circuitry configured to sequentially superimpose and display the simulated dose distributions on an object model.