IMRT

Pa*ent%geometric%uncertain*es:% homogeneous%dose%distribu*ons%

Systema*c%errors% Random%errors%

Smoothing

Shift

Assuming%margins%such%that%90%%of%the%popula*on%receives% 95%%of%prescribed%dose% α =2.5%and%β=1.64%(Van%Herk%et%al)%