TY - JOUR ID - 3098 TI - Size Effects of Gold and Iron Nanoparticles on Radiation Dose Enhancement in Brachytherapy and Teletherapy: A Monte Carlo Study JO - Iranian Journal of Medical Physics JA - IJMP LA - en SN - AU - Ezzati, Ahad Ollah AU - Mahdavi, Seyed Rabi AU - Anijdan, Hossein Mousavie AD - Faculty of Physics, University of Tabriz, Tabriz, Iran AD - Department of Medical Physics, Iran University of Medical Sciences, Tehran, Iran AD - Department of Medical Physics, Babol University of Medical Sciences, Babol, Iran Y1 - 2014 PY - 2014 VL - 11 IS - Issue 2,3 SP - 253 EP - 259 KW - Brachytherapy KW - Dose Enhancement Factor KW - Monte Carlo KW - Nanoparticle DO - 10.22038/ijmp.2014.3098 N2 - Introduction In this study, we aimed to calculate dose enhancement factor (DEF) for gold (Au) and iron (Fe) nanoparticles (NPs) in brachytherapy and teletherapy, using Monte Carlo (MC) method. Materials and Methods In this study, a new algorithm was introduced to calculate dose enhancement by AuNPs and FeNPs for Iridium-192 (Ir-192) brachytherapy and Cobalt-60 (Co-60) teletherapy sources, using the MC method. In this algorithm, the semi-random distribution of NPs was used instead of the regular distribution. Diameters were assumed to be 15, 30, and 100 nm in brachytherapy and 15 and 30 nm in teletherapy. Monte Carlo MCNP4C code was used for simulations, and NP density values were 0.107 mg/ml and 0.112 mg/ml in brachytherapy and teletherapy, respectively. Results AuNPs significantly enhanced the radiation dose in brachytherapy (approximately 60%), and 100 nm diameter NPs showed the most uniform dose distribution. AuNPs had an insignificant effect on teletherapy radiation field, with a dose enhancement ratio of 3% (about the calculation uncertainty) or less. In addition, FeNPs had an insignificant effect on both brachytherapy and teletherapy radiation fields. FeNPs dose enhancement was 3% in brachytherapy and 6% (about the calculation uncertainty) or less in teletherapy. Conclusion It can be concluded that AuNPs can significantly increase the absorbed dose in brachytherapy; however, FeNPs do not have a noticeable effect on the absorbed dose UR - https://ijmp.mums.ac.ir/article_3098.html L1 - https://ijmp.mums.ac.ir/article_3098_97ef2806a0421aa6319b0201a67ce5a2.pdf ER -