Advanced Physics for Brachytherapy 2018

Inverse Optimisation and Planning: A Multi-Objective (MO) Problem

Strong trade-off

Weak trade-off

The “ideal solution/plan” I: I = (f 1,min , f 2,min )

I

I

Examples of a Pareto Front Left: there is a strong trade-off between the objectives/ objective functions f 1 and f 2

. The smaller

the f 1 value is that we want the larger is the corresponding f 2

value . The “ideal point/plan” I lies far

away form the front. There is a high dependence on the selection of the f 1 value .

Right: there is a weak trade-off between the objectives/ objective functions f 1 and f 2

. It is possible

to optimise (minimise) the f 1 we observe a rapid increase of f 2

significant and close to the “ideal point/plan” I. Only very close to I . This is a case where for a set of parameters we can obtain

simultaneously almost individual optimal values for f 1

and f

2