gms | German Medical Science

48th Meeting of the Particle Therapy Co-Operative Group

Particle Therapy Co-Operative Group (PTCOG)

28.09. - 03.10.2009, Heidelberg

Cell survival in carbon beams – comparison of amorphous track model predictions

Meeting Abstract

  • L. Grzanka - Institute of Nuclear Physics, Polish Academy of Science, Kraków, Poland
  • S. Greilich - Division of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
  • M. Korcyl - Institute of Physics, Jagiellonian University, Kraków, Poland
  • N. Bassler - Aarhus Hospital, Department for Experimental Oncology, Aarhus, Denmark
  • O. Jäkel - Division of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
  • M. Waligórski - Centre of Oncology, Kraków, Poland
  • P. Olko - Institute of Nuclear Physics, Polish Academy of Science, Kraków, Poland

PTCOG 48. Meeting of the Particle Therapy Co-Operative Group. Heidelberg, 28.09.-03.10.2009. Düsseldorf: German Medical Science GMS Publishing House; 2009. Doc09ptcog076

DOI: 10.3205/09ptcog076, URN: urn:nbn:de:0183-09ptcog0766

Published: September 24, 2009

© 2009 Grzanka et al.
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Outline

Text

Introduction: Predictions of the radiobiological effectiveness (RBE) play an essential role in treatment planning with heavy charged particles. Amorphous track models ([1], [2], also referred to as track structure models) provide currently the most suitable description of cell survival under ion irradiation. The aim of this paper is to compare the predictions from different amorphous approaches found in the literature - more specifically the phenomenological, analytical model by Katz and co-workers [1] and a Monte-Carlo based full as implemented for example in the local effect model by Scholz et al. [2]. In addition, a new approach based on microdosimetric distributions is presented and investigated [3].

Material and methods: A suitable software library embrasing the mentioned amorphous track models including numerous submodels with respect to delta-electron range models, radial dose distribution models, and gamma response models was developed. This software can be used for direct numerical comparison between the models, submodels and their parameters and experimental data. In the present paper, we look at 10%-survival data from cell lines irradiated in vitro with carbon and proton beams by Tsuruoka et al. [4].

Results and conclusion: Preliminary results show a good agreement of models predictions and the experimental data for clinical doses. When investigating the influence of radial dose distributions on inactivation cross section in the Katz model, we found that one of the most important factors is the normalization of the energy distribution around the particle tracks to the actual LET value. Later on we check what is the effect of radial dose distribution choice on kappa parameter for different types and energy of ions.


References

1.
Katz R, Sharma SC.Response of cells to fast neutrons, stopped pions, and heavy ion beams. Nucl Instrum Meth. 1973;111:93-116.
2.
Weyrather WK, Kraft G. RBE of carbon ions: experimental data and the strategy of RBE calculation for treatment planning. Radiother Oncol. 2004;73(Suppl 2):161-9.
3.
Greilich S, Grzanka L, Bassler N, Andersen CE, Jäkel O. Amorphous track modelling of luminescence detector efficiency in proton and carbon beams.
4.
Tsuruoka C, Suzuki M, Kanai T, et al. LET and ion species dependence for cell killing in normal human skin fibroblasts. Radiat Res. 2005;163:494-500.