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Using an Infinite Von Mises-Fisher Mixture Model to Cluster Treatment Beam Directions in External Radiation Therapy

2010

Conference Paper

ei

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We present a method for fully automated selection of treatment beam ensembles for external radiation therapy. We reformulate the beam angle selection problem as a clustering problem of locally ideal beam orientations distributed on the unit sphere. For this purpose we construct an infinite mixture of von Mises-Fisher distributions, which is suited in general for density estimation from data on the D-dimensional sphere. Using a nonparametric Dirichlet process prior, our model infers probability distributions over both the number of clusters and their parameter values. We describe an efficient Markov chain Monte Carlo inference algorithm for posterior inference from experimental data in this model. The performance of the suggested beam angle selection framework is illustrated for one intra-cranial, pancreas, and prostate case each. The infinite von Mises-Fisher mixture model (iMFMM) creates between 18 and 32 clusters, depending on the patient anatomy. This suggests to use the iMFMM directly for beam ensemble selection in robotic radio surgery, or to generate low-dimensional input for both subsequent optimization of trajectories for arc therapy and beam ensemble selection for conventional radiation therapy.

Author(s): Bangert, M. and Hennig, P. and Oelfke, U.
Pages: 746-751
Year: 2010
Month: December
Day: 0
Editors: Draghici, S. , T.M. Khoshgoftaar, V. Palade, W. Pedrycz, M.A. Wani, X. Zhu
Publisher: IEEE

Department(s): Empirical Inference, Probabilistic Numerics
Bibtex Type: Conference Paper (inproceedings)

DOI: 10.1109/ICMLA.2010.114
Event Name: Ninth International Conference on Machine Learning and Applications (ICMLA 2010)
Event Place: Washington, DC, USA

Address: Piscataway, NJ, USA
Digital: 0
ISBN: 978-1-4244-9211-4

Links: Web

BibTex

@inproceedings{BangertHO2010,
  title = {Using an Infinite Von Mises-Fisher Mixture Model to Cluster Treatment Beam Directions in External Radiation Therapy },
  author = {Bangert, M. and Hennig, P. and Oelfke, U.},
  pages = {746-751 },
  editors = {Draghici, S. , T.M. Khoshgoftaar, V. Palade, W. Pedrycz, M.A. Wani, X. Zhu},
  publisher = {IEEE},
  address = {Piscataway, NJ, USA},
  month = dec,
  year = {2010},
  month_numeric = {12}
}