Fig. 1

Representative sections (axial and sagittal) of a radiotherapy plan show the GTV (red) and PTV (yellow) as well as isodose lines. Despite inhomogeneity in the dose distribution planning, objectives were met. The axial sections show maximal sparing of the left kidney, which is outside the 9 Gy isodose (blue). The dose-volume histogram (DVH) indicates a good dose coverage for both the GTV (red) and PTV (yellow) and respecting of all dose constraints for organs at risk with < 45 Gy maximum dose in 2% of the volume for the spinal cord (dark purple) and low dose to the left kidney (light green)