Method for adjusting a dose distribution setting of a technical device for tumor therapy, - reading a first plan from a data memory; - displaying the first plan of a dose distribution in a plan volume on a display device for a possible setting of the technical apparatus of tumor therapy for delivering the set dose distribution to a patient; wherein a first operating aid and a second operating aid each have two end positions (41, 42), and the first end position of the first operating aid corresponds to the first plan, wherein the second operating aid assigns a navigation plan (11, 12, 13) to the second end position of the first operating aid; - for purpose of changing or amending the first plan in at least one volume-specified fineness and drawing up or determining a causal follow-up plan for adjustment on/at the technical device of tumor therapy; - presetting of a new dose value for a local group of voxels (z) in or as the volume-specified fineness at a certain position of the planned volume, which does not have this new dose value, - wherein the specific location is determined by selecting an initial voxel, which is located in a layer (yi) of the plan volume; - conversion of the first plan into a first navigation plan, which conversion takes into account the first plan and the dose change in the local voxel group; - wherein the first plan is converted into a second navigation plan in accordance with the first conversion and with presetting of mathematical weights in the conversion, so that first and second navigation plans (11, 12) are different, wherein the mathematical weights increase with increasing distance from the initial voxel and the second navigation plan has more locally limited changes compared with the first navigation plan; - and the second operating device or aid has a plurality of intermediate positions, each of which corresponds to an intermediate plan, each of the intermediate plans corresponding to an interpolation between the first navigation plan and the second navigation plan, and a selected intermediate position defining a respective third navigation plan as a mixed plan; - wherein between the two end positions of the first operating aid there are a plurality of intermediate positions, each of which corresponds to an intermediate plan, and each of the intermediate plans corresponds to an interpolation from the first plan in the direction of the navigation plan (11, 12, 13); - displaying a plan (10, 11, 12, 13) on the display device, depending on a setting of the first operating aid. - reading a first plan from a data memory; - displaying the first plan of a dose distribution in a plan volume on a display device for a possible setting of the technical apparatus of tumor therapy for delivering the set dose distribution to a patient; wherein a first operating aid and a second operating aid each have two end positions (41, 42), and the first end position of the first operating aid corresponds to the first plan, wherein the second operating aid assigns a navigation plan (11, 12, 13) to the second end position of the first operating aid; - for purpose of changing or amending the first plan in at least one volume-specified fineness and drawing up or determining a causal follow-up plan for adjustment on/at the technical device of tumor therapy; - presetting of a new dose value for a local group of voxels (z) in or as the volume-specified fineness at a certain position of the planned volume, which does not have this new dose value, - wherein the specific location is determined by selecting an initial voxel, which is located in a layer (yi) of the plan volume; - conversion of the first plan into a first navigation plan, which conversion takes into account the first plan and the dose change in the local voxel group; - wherein the first plan is converted into a second navigation plan in accordance with the first conversion and with presetting of mathematical weights in the conversion, so that first and second navigation plans (11, 12) are different, wherein the mathematical weights increase with increasing distance from the initial voxel and the second navigation plan has more locally limited changes compared with the first navigation plan; - and the second operating device or aid has a plurality of intermediate positions, each of which corresponds to an intermediate plan, each of the intermediate plans corresponding to an interpolation between the first navigation plan and the second navigation plan, and a selected intermediate position defining a respective third navigation plan as a mixed plan; - wherein between the two end positions of the first operating aid there are a plurality of intermediate positions, each of which corresponds to an intermediate plan, and each of the intermediate plans corresponds to an interpolation from the first plan in the direction of the navigation plan (11, 12, 13); - displaying a plan (10, 11, 12, 13) on the display device, depending on a setting of the first operating aid.