eng Oriental Scientific Publishing Company Biomedical and Pharmacology Journal 0974-6242 2015-04-28 6 2 205 213 10.13005/bpj/404 2688 article Mansour Zabihzadeh1 1,3 Ali Yadollahpour 1 Leila Kargar 1 Department of Medical Physics, School of Medicine, Jundishapur University of Medical Sciences, Ahvaz, Iran. Department of Radiation Oncology, Golestan Hospital, Jundishapur University of Medical Sciences, Ahvaz, Iran. The present study examines the effects of dose variation on brachytherapy treatment with Ir-192 source in the presence and absence of tissue heterogeneities.The effect of source location and distance between the heterogeneity and the source on dose distribution were evaluated using Monte Carlo simulation (MCNP4C code). Soft tissue heterogeneity showed no significant effect on dose distribution. Increasing the distance between the source and the phantom center, decreases dose delivery because of reduced scattering. Despite the surrounding heterogeneities, Ir-192 source can alter dose distribution in comparison with the homogeneous water phantom. https://biomedpharmajournal.org/vol6no2/the-effects-of-tissue-heterogeneitieson-dose-distribution-of-iridium-192-source-in-brachytherapy-treatments/ Dose distribution High-dose rate (HDR)brachytherapy Iridium-192 source Tissue heterogeneities Monte Carlo simulation