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

Beam model used in treatment planning for carbon-ion scanning with range shifter plates

Meeting Abstract

  • T. Inaniwa - Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba, Japan
  • T. Furukawa - Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba, Japan
  • S. Sato - Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba, Japan
  • A. Nagano - Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba, Japan
  • N. Saotome - Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba, Japan
  • N. Kanematsu - Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba, Japan
  • K. Noda - Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, Chiba, Japan

PTCOG 48. Meeting of the Particle Therapy Co-Operative Group. Heidelberg, 28.09.-03.10.2009. Düsseldorf: German Medical Science GMS Publishing House; 2009. Doc09ptcog095

doi: 10.3205/09ptcog095, urn:nbn:de:0183-09ptcog0951

Published: September 24, 2009

© 2009 Inaniwa et al.
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Outline

Text

In order to use an intensity-controlled raster scan method at the new treatment facility in HIMAC, we have developed a code system dedicated to the planning of radiotherapy with the scanned 12C beam. In the code, the lateral dose distributions of the pencil beam has been expressed by a single Gaussian with the spread depending on the depth and the thickness of the range shifter plate. The effect of the beam spread due to multiple scattering in the range shifter plates can be included in this model, at least for the primary particles. However, our recent research revealed that the large-angle scattered fragments affect the dose far away from the track of the primary particles and make the doses within the target volume dependent on the field size. In order to account for the observed dependencies, we proposed to express the lateral dose distribution of the scanned carbon beam by sum of three Gaussians. In the meeting, the detailed explanations of the model and the experimental results with it will be shown, in addition to the current status of the development of the treatment planning code.