Fig. 1: Mouse model and μCT.

a, LM8 osteosarcoma as visible by eye or at the μCT at different times after cell inoculation. Green lines depict the GTV contours of the tumours. For the irradiation, a 2-week timepoint was chosen. b, Two slices of the CT depicting the contours of the individual tumour GTVs (green) near the OARs (spine and trachea with lungs, marked with yellow and blue, respectively). The generalized CTV contour (purple) was applied to all animals, covering all the possible GTV locations previously identified in the tumour induction study. Not all the GTVs are depicted here, as some of them were located on the different neighbouring CT slices. c, The CTV obtained from the contours of individual GTVs of tumours that grew in the animals used to establish and confirm the tumour model. To account for further biological variation, the resulting contour was smoothened and made symmetrical with respect to the spine. The CTV is depicted in purple; the mouse skeleton is shown in light yellow; the trachea and the lungs are shown in blue. The light-grey colour depicts the contours of the mouse body.