@article{A08b,
Author = {A. Schlaefer and O. Blanck},
Title = {TU-EE-A1-05: Exploring the Spatial Trade-Off in Treatment Planning.},
Journal = {<em>Medical Physics</em>.},
Year = {(2008).},
Volume = {<strong>35</strong>.},
Number = {(6),},
Pages = {2910},
Booktitle = {<em>Medical Physics</em>},
Doi = {10.1118/1.2962609},
Abstract = {Purpose: To include spatial information during multi\-criteria treatment planning. Particularly, to study whether constrained optimization on the voxel level allows to deliberately trade\-off the dose delivered to one region of a volume of interest (VOI) with respect to other clinical goals. Method and Materials: We extended a stepwise optimization method for roboticradiosurgery to interactively modify dose constraints on a voxel level. The optimization problem is solved using linear programming, and every term in the objective function is matched by a corresponding constraint. Clinical goals are addressed separately and maintained using the constraints. A trade\-off among the clinical goals is then explored by a series of optimization steps. For visualization, VOIs are represented by a 3D grid of spheres, where each sphere represents a voxel and can be selected in a 3D scene. Constraints on the dose in the selected voxels can be considered independently for subsequent optimization steps. The method was applied to a prostate case, where we studied trade\-offs with respect to the maximum dose in the rectum. Results: Relaxing the upper dose bound on a set of voxels in the prostate lobes by 150 cGy allowed to reduce the maximum rectum dose by 100 cGy. Likewise, a relaxation of the lower dose bound on a few voxels on the prostate surface by 100 cGy allowed to further reduce the maximum dose in th rectum by 157 cGy. Conclusion: Spatial information is not available from cumulative statistics typically used as criteria for treatment planning. Our results indicate that it is possible to include spatial information in interactive multi\-criteria optimization. The proposed method can be used when clinical goals can be expressed with respect to a subregion of a VOI. Conflict of Interest: Research partially sponsored by Accuray Inc}
}

@COMMENT{Bibtex file generated on 2026-5-12 with typo3 si_bibtex plugin. Data from https://www.tuhh.de/mtec/publications/2012-2000 }