IMRT

Stochastic method

Dose in voxel i is a sum of the doses coming out of each bixel, weighed with the constraints

d i j ∑ Normal Optimization ( x ) = D ij x j

Is our IMRT objective function which has to be minimized

f ( d ( x ))

Robust Optimization

Dose is calculate for all different scenarios = e.g. all possible positions

j ∑

( x ) = D s ij

d s i

x j

The objective function is now minimized over all possible scenarios, weighed with the probability function

s ∑

f ( d s ( x ))

< f >= p s