ESTRO 2022 - Abstract Book

S574

Abstract book

ESTRO 2022

Conclusion For all shapes, margin-based plans provided adequate coverage, but high and intermediate dose regions extended further than in robustly optimised plans. The robust plans under-dose small parts of most shapes except for the sphere. This is likely due to the ‘corners’ of the shape not being covered in the high dose region because the robustness algorithm only samples errors in cardinal directions. We conclude that margin plans are safe for all tested shapes, but that robust planning