A medical instrument (100, 200, 400, 500) comprising: - a user interface comprising a display; - a memory storing machine executable instructions; - a computational system configured for controlling the medical instrument, wherein execution of the machine executable instructions causes the computational system to: - receive an anatomical segmentation identifying a location of an anatomical structure; - receive a target zone segmentation identifying a location of a volume at least partially within the anatomical segmentation; and - display a planning graphical user interface using the display; wherein the planning graphical user interface comprises a first panel configured for rendering a cross sectional view of the anatomical segmentation and the target zone segmentation; wherein the planning graphical user interface further comprises a second panel configured for displaying a rendering of a first three-dimensional model of the anatomical segmentation and the target zone segmentation; wherein the planning graphical user interface further comprises a third panel configured for rendering a second three-dimensional model of a remaining portion of the target zone segmentation; wherein the planning graphical user interface further comprises an ablation selector (144, 144', 146) configured to provide a user-selectable ablation zone, descriptive of a volume at least partially within the remaining portion that the user can select to ablate the target zone segmentation; wherein execution of the machine executable instructions further causes the computational system to iteratively: - receive an ablation zone from the ablation selector (144, 144', 146); and - update the remaining portion by removing the ablation zone from the remaining portion, until the corresponding iterations are finished. - a user interface comprising a display; - a memory storing machine executable instructions; - a computational system configured for controlling the medical instrument, wherein execution of the machine executable instructions causes the computational system to: - receive an anatomical segmentation identifying a location of an anatomical structure; - receive a target zone segmentation identifying a location of a volume at least partially within the anatomical segmentation; and - display a planning graphical user interface using the display; wherein the planning graphical user interface comprises a first panel configured for rendering a cross sectional view of the anatomical segmentation and the target zone segmentation; wherein the planning graphical user interface further comprises a second panel configured for displaying a rendering of a first three-dimensional model of the anatomical segmentation and the target zone segmentation; wherein the planning graphical user interface further comprises a third panel configured for rendering a second three-dimensional model of a remaining portion of the target zone segmentation; wherein the planning graphical user interface further comprises an ablation selector (144, 144', 146) configured to provide a user-selectable ablation zone, descriptive of a volume at least partially within the remaining portion that the user can select to ablate the target zone segmentation; wherein execution of the machine executable instructions further causes the computational system to iteratively: - receive an ablation zone from the ablation selector (144, 144', 146); and - update the remaining portion by removing the ablation zone from the remaining portion, until the corresponding iterations are finished. - receive an ablation zone from the ablation selector (144, 144', 146); and - update the remaining portion by removing the ablation zone from the remaining portion, until the corresponding iterations are finished.