Document Type : Original Paper
Authors
1
Department of Nuclear Physics, Faculty of Science, University of Mazandaran P.O.Box 47415-416, Babolsar, Iran
2
Department of Nuclear Physics, Faculty of Science, University of Mazandaran, P. O. Box 47415-416, Babolsar, Iran
3
Department of Physics, Faculty of Science, University of Guilan, Rasht, Iran
4
Golestan university faculty of science, department of physics, Golestan, Iran
Abstract
The GEANT4 Monte Carlo toolkit was utilized to perform radiation transport and dose distribution calculations in brain carbon therapy. To accurately determine the deposited dose received by both involved and noninvolved organs, it is crucial to model a human phantom. We created Spread Out Bragg Peak by using weights factors. The phantom used to simulate brain tumor carbon therapy is a human Oak Ridge National Laboratory-Medical Internal Radiation Dose. The appropriate carbon energy range that covers the entire brain tumor area was in the range of 2420-2560 MeV. We need to create SOBP to calculate a uniform dose distribution in the tumor volume in carbon therapy. We can be produced a SOBP by using several Bragg Peaks in different energy ranges and with certain intensities factors to cover the target volume. The required beam parameters are evaluated from the International Commission on Radiation Units and Measurements. The flux and dose distributions of secondary particles were determined and estimated on the brain tumor and surrounding tissues. The secondary particles include protons, electrons, neutrons, alpha and photons. Finally, the total dose and flux due to the carbon ions and secondary particles were calculated in target volume and other several healthy organs. It was observed that the amount of reached dose to the healthy brain tissue compared to the reached dose to the tumor was equal to 0.003. This value for other organs, such as the skull and thyroid, were 4.8 ×10-4 and 2.6×10-5, respectively. Because neutrons and photons delivered most of their energy to organs with a greater distance from the target volume, they increase the risk of secondary cancers. The findings presented in this article indicate that the dose generated by secondary particles in the brain and other organs is negligible, with the maximum absorbed dose occurring in the tumor.
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