School of Physics, Damghan University, P.O. Box 36716-41167, Damghan, Iran , tajik@du.ac.ir
Abstract: (55 Views)
Background:In this study, Monte Carlo simulations were performed to estimate the dose of proton therapy to involved and uninvolved organs in gastric cancer. Materials and Methods: The dose received by involved and uninvolved organs during gastric treatment was simulated during pencil beam scanning proton therapy using the MIRD-UF phantom and the MCNPX code. In this modeling, the appropriate energy range for tumor treatment in the gastric tissue of an adult male MIRD-UF phantom with monoenergetic proton beams was calculated. The dose secondary charged particles, neutrons and photons in the tumor and vital organs were evaluated. Results: The results showed that, depending on the size of the tumor, the appropriate and optimal range of proton energy to cover the tumor is 67 - 81.5 MeV. The distribution of energy deposition, total primary dose, and the ratio of neutron equivalent dose to absorbed therapeutic dose (H/D) were calculated for the tumor and 12 vital organs. The ratio between the total received dose of the healthy gastric tissue and the delivered dose of the tumor was about 0.0046. The average photon equivalent dose was about 0.9% of the neutrons. The highest H/D ratios for normal stomach, spleen, pancreas, and left kidney tissue were 0.167 mSv/Gy, 0.0362 mSv/Gy, 0.0231 mSv/Gy and 0.0143 mSv/Gy, respectively. Conclusion: In the study, a small gastric tumor in an adult male phantom was irradiated with high-energy protons. Proton therapy delivered the highest possible dose to the tumor, while the healthy organs received a low dose.