Advanced Physics for Brachytherapy 2018

Inverse Optimisation and Planning

Create a single Objective Function via weighted Aggregation

The minimisation of the Aggregated Objective Function f can be interpreted as finding the value f for which the line with slope –w 1 /w 2 just touches the boundary of F as it proceeds outwards from the origin.

w1 f1 + w2 f2 ???

Pareto Front

Empirically estimated penalisation schemes, found to result to „good“ dose distributions are ussually saved as presets / protocols / class solutions and can be used as starting points for the individual patient plan optimisation process. The plan/solution which is obtained in the Weighted Aggregation approach depends on the shape of the Pareto Front and the importance factors/penalties used. Planner is not aware if there exist a better “choice” on the Pareto Front just next door!