Friday September 24 at 11.00 Lindstedtsvägen 25, room 3721
RaySearch Laboratories and
Division of Optimization and Systems Theory,
Department of Mathematics, KTH.
Minimax optimization for handling range and setup uncertainties
in proton therapy
Intensity modulated proton therapy (IMPT) for cancer treatment allows for
dose distributions that conform closely to the target volume. Resulting
treatment plans are however sensitive to errors and conventional margins
around the regions of interest are often insufficient to ensure robustness.
To obtain robust plans, we perform minimax optimization, taking range and
setup uncertainties into account. This method is related to stochastic
programming by the more general minimax stochastic programming formulation.
We apply the minimax
method to a lung case, a paraspinal case, and a prostate case.
Resulting plans are compared to plans for which conventional
methods are used to handle the uncertainties. For all cases, the minimax
method provides more robust target coverage and better sparing of healthy
tissues than the other methods. By incorporating information about the
uncertainties into the optimization, the modality can be better utilized and
some of the problems associated with margins in IMPT can be eliminated.
Calendar of seminars
Last update: September 16, 2010.