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Aim
Mitigate the influence of uncertainties in IMPT and limit dose degradation due to
un-intended range variations
How
Include uncertainties in the optimization process
Robust optimization
Errors in patient positioning (setup errors) and range errors are
explicitly included in plan optimization, optimizing the expected value or worst-case
value of the objective function or individual objectives
NB
the optimization target is the CTV
E.g.
Worst case scenario – minimizes the penalty of the worst scenario (among a
limited number of error scenarios), with no regards to the probabilities of the scenarios.
It may result in overlay conservative plans
Price
of robustness? OARs dose, but could be better than the PTV approach
Robust evaluation: Incorporate the impact of uncertainties when evaluating
an IMPT plan
Robust Optimization