Monte Carlo simulation of secondary neutron dose in major organs in RPI-Adult male phantom during carbon ion radiotherapy(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2017年第12期
- Page:
- 1189-1195
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- Monte Carlo simulation of secondary neutron dose in major organs in RPI-Adult male phantom during carbon ion radiotherapy
- Author(s):
- SUN Taojun; LIU Hongdong; CHEN Zhi; XU Xie
- School of Nuclear Science and Technology, University of Science and Technology of China, Hefei 230025, China
- Keywords:
- ; Monte Carlo method; voxel phantom; carbon ion; equivalent dose
- PACS:
- R811.1；TL72
- DOI:
- DOI:10.3969/j.issn.1005-202X.2017.12.001
- Abstract:
- Abstract: Objective To calculate the absorbed secondary neutron dose and the equivalent dose in the major organs during carbon ion radiotherapy using the Monte Carlo method. Methods Based on the beam delivery system for heavy ion deep tumor treatment developed by the Institute of Modern Physics (IMP), Chinese Academy of Sciences, we constructed the models of the primary collimator, ridge filter, range shifter, and multi-leaf collimator using MCNPX code. We recorded the absorbed secondary neutron dose, equivalent dose and energy spectrum in the major organs when the RPI-Adult male phantom was exposed to a beam of 12C ions with an energy level of 400 MeV/u delivered via the IMP passive beam delivery system. Results For treatment of pituitary tumors, a prescribed dose at 50 Gy resulted in a wide energy range in the organs, as shown by the neutron energy spectrum, and the maximum energy could reach even several hundreds of MeV. The secondary neutron equivalent doses were also high in the organs close to the target including the brain, cranium and eye lens (53.18, 32.43 and 33.20 mSv, respectively), but in the more distal organs (such as the breasts, lungs and prostate), the equivalent doses were rather low (all below 4 mSv). Conclusion We successfully simulated the process of carbon ion radiotherapy using the Monte Carlo method and computational voxelized human phantom. The secondary neutron energy spectrum and dose distribution in the major organs in this simulation can provide a reference for clinical evaluation of the long-term effects of the carbon ion radiotherapy.
Last Update: 2017-12-20