%0 Generic
%A Krauß, Andreas
%D 2012
%F heidok:13118
%K Strahlentherapie , Organbewegungen , Lamellenkollimatorradiation therapy , organ motion , multileaf collimator
%R 10.11588/heidok.00013118
%T Compensation of intra-fractional organ motion through multileaf collimator tracking
%U https://archiv.ub.uni-heidelberg.de/volltextserver/13118/
%X In this thesis, we present substantial improvements and extensions of a previously inhouse developed multileaf collimator (MLC) tracking system. The MLC tracking system compensates for intra-fractional organ motion by adapting the aperture of a dynamic MLC in real-time to continuously monitored target motion. Our main improvements are: Firstly, the integration of clinically applicable intra-fractional motion monitoring devices based on implanted electromagnetic transponders, a novel x-ray imaging system or a combined external surrogate monitoring and x-ray imaging system. Secondly, the implementation of state-of-the-art respiratory motion forward prediction models to compensate for total system latencies of 0.5 s to 0.6 s. Thirdly, a complete redesigned of the MLC control software towards a high level of application reliability and stability as well as software maintainability and further extendability. We assess the tracking performance in various phantom experiments with sinusoidal, irregular breathing and prostate trajectories. We can reduce the remaining geometric MLC tracking uncertainties to the respiratory motion forward prediction error. Our film dosimetry evaluations demonstrate that the integrated MLC tracking system can largely eliminate the negative effects of intra-fractional organ motion on the dose distribution.