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

Simulation system of positron emitter nuclei distribution in a patient body using target elemental activity pencil beam algorithm in proton therapy

Meeting Abstract

  • A. Miyatake - Particle Therapy Division, National Cancer Center, Kashiwa, Chiba, Japan
  • T. Nishio - Particle Therapy Division, National Cancer Center, Kashiwa, Chiba, Japan
  • T. Tachikawa - Quantum Equipment Division, Sumitomo Heavy Industries, Ltd., Ehime, Japan
  • M. Yamada - Quantum Equipment Division, Sumitomo Heavy Industries, Ltd., Ehime, 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. Doc09ptcog138

DOI: 10.3205/09ptcog138, URN: urn:nbn:de:0183-09ptcog1388

Published: September 24, 2009

© 2009 Miyatake et al.
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Outline

Text

In proton therapy, the irradiation dose can be concentrated on a tumor using a scanned or modulated Bragg peak. Therefore, it is very important to evaluate the proton-irradiated volume accurately. The proton-irradiated volume can be confirmed by detection of pair-annihilation gamma rays from positron-emitting nuclei generated by the target nuclear fragment reactions of the incident protons on target nuclei using a beam ON-LINE PET system mounted on a rotating gantry port (BOLPs-RGp) developed at the National Cancer Center Kashiwa, Japan. The verification of the proton-irradiated volume was performed by simulation of the activity distribution in a patient body. One of simulation of the activity distribution is Monte Carlo simulation code such as GEANT and FLUKA included values of reaction cross section of the target nuclear fragment reactions. The volume and precision of reaction cross section data of the target nuclear fragment reaction between incident proton nuclei and C, N, O and Ca nuclei at the therapeutic proton energy of 0–250MeV will be insufficient for the calculation of the activity distribution. It is difficult to simulate monitoring the proton-irradiated volume in the patient's body accurately at present. Also, the overly long calculation time will be not so realistic for clinical use. Therefore, the simulation system for activity distribution calculation with high speed and high precision is necessary. We developed the target elemental activity pencil beam algorithm (TEA-PBA) in proton therapy. Measured depth activity distribution of positron emitter nuclei generated from 12C, 16O and 40Ca nuclei of mainly human body composition with the BOLPs-RGp is used in the TEA-PBA. The pencil beam kernel of activity taking into account the multiple coulomb scattering of proton beam in the compound is calculated at each depth of the measured activity. A proton beam was irradiated to water, polyethylene and calcium oxide including 12C, 16O and 40Ca for the measured depth activity distribution. Furthermore, the activity distribution of MONO beam was converted into the activity distribution of SOBP beam using information of the beam modulation. The developed TEA-PBA enabled the activity distribution calculation with high speed and high precision. And, the simulation system will be used in clinical proton therapy (Figure 1 [Fig. 1], Figure 2 [Fig. 2], Figure 3 [Fig. 3]).