Distributions of positron-emitting nuclei in proton and carbon-ion therapy studied with GEANT4

Abstract

Depth distributions of positron-emitting nuclei in PMMA phantoms are calculated within a Monte Carlo model for Heavy-Ion Therapy (MCHIT) based on the GEANT4 toolkit (version 8.0). The calculated total production rates of ${}^{11}$C, ${}^{10}$C and ${}^{15}$O nuclei are compared with experimental data and with corresponding results of the FLUKA and POSGEN codes. The distributions of e${}^{+}$ annihilation points are obtained by simulating radioactive decay of unstable nuclei and transporting positrons in surrounding medium. A finite spatial resolution of the Positron Emission Tomography (PET) is taken into account in a simplified way. Depth distributions of ${\beta }^{+}$-activity as seen by a PET scanner are calculated and compared to available data for PMMA phantoms. The calculated ${\beta }^{+}$-activity profiles are in good agreement with PET data for proton and ${}^{12}$C beams at energies suitable for particle therapy. The MCHIT capability to predict the ${\beta }^{+}$-activity and dose distributions in tissue-like materials of different chemical composition is demonstrated.

16 pages, 4 figures

References in corpus (1)

• Neutrons from fragmentation of light nuclei in tissue-like media: a study with GEANT4 toolkit

Cited by in corpus (1)

• Ion-induced electron production in tissue-like media and DNA damage mechanisms