Navigable presentation of a variety of solutions for therapy plans

A system as a planning tool for interactively selecting solutions during an interactive navigation of a user, the system comprising:

• a display device (20) for displaying graphs of dose/volume histograms (30) for the interactive navigation, wherein each dose/volume histogram has a number of dose/volume histogram curves;
• a visualization module (11) operating for buffering solutions read out from a database (10) via a data path (15), wherein the solutions are processed such that they are provided to the display device as a screen signal, and the screen signal yields a representation on the display device;
• wherein the visualization module is configured to:
• display a first dose/volume histogram as a main diagram, wherein one of a plurality of pre-calculated stored solutions from the database is visually represented at a time for manually selecting a first starting point (41a) on one, thereby selecting a curve (40a) of the number of dose/volume histogram curves and displaying a first straight axis (71,73) extending through the first starting point (41a);
• optically highlight a first region (72,74), located around the first starting point (41a) and on the first straight axis (71, 73), as a first straight portion having an upper and a lower limit to visualize, by a length extension between the limits, un-displayed solutions as stored and present in the database, but un-displayed by shapes of the curves,
• wherein the length of the first straight portion is defined by all points of intersections of the dose/volume histogram curves corresponding to the selected dose/volume histogram curve (40a).