2014
Sachpazidis, Ilias; Baltas, Dimos; Sakas, Georgios
Simulation and Optimization of Brachytherapy High Dose Rate plans Conference
6th International Conference in textquotedblleftScientific Computing to Computational Engineeringtextquotedblright 6th IC-SCCE, Athens, Greece, 2014.
Abstract | BibTeX | Tags: Brachytherapy, Inverse optimization
@conference{40,
title = {Simulation and Optimization of Brachytherapy High Dose Rate plans},
author = {Ilias Sachpazidis and Dimos Baltas and Sakas, Georgios},
year = {2014},
date = {2014-01-01},
booktitle = {6th International Conference in textquotedblleftScientific Computing to Computational Engineeringtextquotedblright 6th IC-SCCE},
address = {Athens, Greece},
abstract = {In this paper we are going to describe a brachytherapy planning system and the related optimization algorithms for optimization planning. Brachytherapy is an advanced cancer treatment. Radioactive sources are placed in or near the tumor itself, giving a high radiation dose to the tumor while reducing the radiation exposure in the surrounding healthy tissues. In addition, our scope is to present the scientific results of CEIROS EUROSTARS project and describe the mathematical and partly the physical background for the use of both DVH and gEUD concept for High Dose Rate (HDR) optimization. The concept of equivalent uniform dose (EUD) for tumors was introduced as the biologically equivalent dose that, if given uniformly, would lead to the same cell kill in the tumor volume as the actual non-uniform dose distribution. Later, it is extended to apply to normal tissues as well. Presently, most optimization systems use dose and/or dose–volume-based objective functions. Neither adequately represents the nonlinear response of tumors or normal structures to dose, especially for arbitrary inhomogeneous dose distributions. For instance, if a single voxel or a small number of voxels in a tumor receive a very low dose, it would not have a significant effect on the plan score. However, the tumor control probability would be greatly diminished as a result of the cold spot. Stated in a different way, for dose- or dose–volume-based objective functions, the penalty imposed for the failure to achieve the prescribed dose is proportional to the dose difference (or the square of the difference), rather than to the loss of tumor control, as would be more appropriate.},
keywords = {Brachytherapy, Inverse optimization},
pubstate = {published},
tppubtype = {conference}
}
In this paper we are going to describe a brachytherapy planning system and the related optimization algorithms for optimization planning. Brachytherapy is an advanced cancer treatment. Radioactive sources are placed in or near the tumor itself, giving a high radiation dose to the tumor while reducing the radiation exposure in the surrounding healthy tissues. In addition, our scope is to present the scientific results of CEIROS EUROSTARS project and describe the mathematical and partly the physical background for the use of both DVH and gEUD concept for High Dose Rate (HDR) optimization. The concept of equivalent uniform dose (EUD) for tumors was introduced as the biologically equivalent dose that, if given uniformly, would lead to the same cell kill in the tumor volume as the actual non-uniform dose distribution. Later, it is extended to apply to normal tissues as well. Presently, most optimization systems use dose and/or dose–volume-based objective functions. Neither adequately represents the nonlinear response of tumors or normal structures to dose, especially for arbitrary inhomogeneous dose distributions. For instance, if a single voxel or a small number of voxels in a tumor receive a very low dose, it would not have a significant effect on the plan score. However, the tumor control probability would be greatly diminished as a result of the cold spot. Stated in a different way, for dose- or dose–volume-based objective functions, the penalty imposed for the failure to achieve the prescribed dose is proportional to the dose difference (or the square of the difference), rather than to the loss of tumor control, as would be more appropriate.