assessment the effect of kidney internal structure on gamma absorbed dose of radiopharmaceutical 111in-dtpa

large quantities of radiopharmaceuticals prescribed for treatment and diagnosis are excreted through kidney. therefore, radiation unwanted dose is created in kidney. as a result, exact calculation of prescribed radiopharmaceuticals amount is important. monte carlo method is used for simulation of radiation transport in body due to random nature of radiation. in this research, for the first time kidney is considered integrated and for the second time it is considered that it has three areas; gamma absorbed dose is calculated and compared in cortex and medulla kidney using mcnpx code to identify a more accurate way to prescribe radioisotope. the results showed that gamma absorbed dose in medulla is 2 times as much as dose in integrated kidney and gamma dose in cortex is about 62% as much as dose in integrated kidney. internal structure of kidney should be considered in simulation to achieve a more accurate prescribed dose