Radiotherapy treatment planning with multiple inverse planning results

An apparatus for inverse planning a radiotherapy treatment of a target volume in a body comprising a display and a logic device which calculates the results of multiple treatment solutions based on a first objective function indicating a desired distribution of dose in a plurality of volume elements within the target volume and a second objective function indicating a desired distribution of dose in a plurality of volume elements within the non-target volume, and causes to be simultaneously displayed on the display the calculated results for at least two of the treatment solutions for comparison by a treatment planner to enable the treatment planner to select a desired one of the treatment solutions, wherein the logic device calculates results of multiple treatment solutions at two or more discrete calculations with different risk organ weightings, and the multiple treatment solutions are obtained from calculations combining non-constrained and constrained steps with variable weighting, thereby enabling consideration of the objective functions without eliminating the possibility to improve the treatment plan beyond the objective functions.