Advanced Physics for Brachytherapy 2018

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

Pareto Front (PF): non-dominated solutions/plans

OAR

F: Feasible

solutions/plans

Overdosage

Underdosage of CTV/PTV

Example of a bi-objective space (f 1 , f 2

) . We assume as mentioned already the minimization

problem. The Pareto Front is the boundary between the points P 1

and P

2 of the feasible set F .

Solutions 1 and 3 are non-dominated Pareto optimal solutions . Solution 2 is not Pareto Optimal as solution 1 has simultaneously smaller values for both objectives. There is no reason why solution 2 should be accepted rather than solution 1. Therefore the aim of MO optimisation is to obtain a representative set of non- dominated solutions.