A Monte Carlo Study on the Effect of Various Neutron Capturers on Dose Distribution in Brachytherapy with 252Cf Source

Shiraz University of Medical Sciences

M M Firoozabadi¹  Gh Izadi Vasafi¹ 

[1]University of Birjand

关键词: Brachytherapy;    Neutron Capture;    252Cf;    Dose;    MCNP;   

DOI  :  

学科分类：生物科学（综合）

来源: Shiraz University of Medical Sciences

【 摘 要 】

Background:In neutron interaction with matter and reduction of neutron energy due to multiple scatterings to the thermal energy range, increasing the probability of thermal neutron capture by neutron captures makes dose enhancement in the tumors loaded with these materials.  Objective:The purpose of this study is to evaluate dose distribution in the presence of  10B ,  157Gd  and  33S  neutron capturers and to determine the effect of these materials on dose enhancement rate for  252Cf  brachytherapy source.  Methods:Neutron-ray flux and energy spectra, neutron and gamma dose rates and dose enhancement factor (DEF) are determined in the absence and presence of  10B ,  157Gd  and  33S  using Monte Carlo simulation.  Results:The difference in the thermal neutron flux rate in the presence of  10B  and  157Gd  is significant, while the flux changes in the fast and epithermal energy ranges are insensible. The dose enhancement factor has increased with increasing distance from the source and reached its maximum amount equal to 258.3 and 476.1 cGy/h/µg for  157Gd  and  10B , respectively at about 8 cm distance from the source center. DEF for 33S is equal to one.  Conclusion:Results show that the magnitude of dose augmentation in tumors containing  10B  and  157Gd  in brachytherapy with  252Cf  source will depend not only on the capture product dose level, but also on the tumor distance from the source.  33S  makes dose enhancement under specific conditions that these conditions depend on the neutron energy spectra of source, the  33S  concentration in tumor and tumor distance from the source.

【 授权许可】

CC BY