تخمین دز پروستات و اندام های مجاور آن در حین براکی تراپی پروستات و بررسی پراکندگی بر میزان دز با استفاده از کد MCNP4C

In regard with increasing use of brachytherapy for treatment of cancer, especially prostate cancer, dosimetry of the organs surrounding prostate is necessary. The received dose by prostate is relatively high and the healthy organs surrounding prostate are potentially at a risk of high dose too. In this paper, the doses delivered to the prostate and organs of interest were calculated by MCNP4C code. Moreover, the effects of scattering from legs on dose distribution of the related organs were evaluated. First, the imparted energies to the organs delivered by 125I were obtained. Then the doses per transformations were calculated by using the volumes and densities of the organs and as a result, the doses to the organs were determined using the activity of the source. Dose to the prostate as a source of radiation was obtained in excess of 100 Gy. Bladder, testes and sigmoid Colon received higher dose than the other organs due to proximity to the prostate. The values of them were 9.45, 4.83 and 2.88 Gy, respectively. The differences between the dose with scattering from the legs of the phantom and without it for testes and sigmoid colon were the highest because of their proximity to the prostate and obtained to be 14.5% and 6.3%. This difference was not considerable for the other organs.