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Treatment planning optimization for non-coplanar volumetric modulated arc therapy

Abstract : Non-coplanar VMAT has the potential to treat tumors that are located in close proximity of critical organs or that are partially surrounded by normal tissues. The use of dynamic couch-gantry trajectories offers an opportunity for more precise and accurate delivery of radiation during cancer treatments.Despite the improvements that have been seen in non-coplanar VMAT, challenges still persist.In this thesis, we present a methodology for the determination of collision free couch-gantry orientations. This methodology is proposed to avoid the possibility of a collision during the motion of the couch and gantry during treatment.We propose an algorithm based on simulated annealing for non-coplanar VMAT treatment planning. This algorithm is used to select the best possible beam orientations for the accurate delivery of the prescribed dose.We also propose a RRT inspired algorithm for generating the trajectory for the non-coplanarVMAT plan delivery. The algorithm is proposed to solve the problem of the addition of intermediate beam orientations observed in beam selection methods.From the results of studies on the proposed methods, improvements to collision detection, global optimization and trajectory generation for non-coplanar VMAT treatment planning were observed. These improvements include a better dosimetry with respect to reductions in mean dose to the organs-at-risk and a more efficient delivery trajectory.Our studies indicate that there exists a reasonable trade-off between treatment plan quality and plan deliverability if the dosimetry of the VMAT treatment plan is continuously monitored during trajectory generation.
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Submitted on : Monday, October 18, 2021 - 5:52:11 PM
Last modification on : Monday, April 4, 2022 - 9:28:21 AM
Long-term archiving on: : Wednesday, January 19, 2022 - 9:46:23 PM


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  • HAL Id : tel-03384158, version 1


Franklin Okoli. Treatment planning optimization for non-coplanar volumetric modulated arc therapy. Human health and pathology. Université de Bretagne occidentale - Brest, 2020. English. ⟨NNT : 2020BRES0061⟩. ⟨tel-03384158⟩



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