Determination of effective dose distribution on the target volume of cancer and organ at risk using MCNPX

One method of therapy in cancer is Brachytherapy. which is by implanting radioactive radiation that emits gamma into the target organ. Because brachytherpy will also provide radiation doses to healthy organs around it so before doing therapy it is better to do the simulation first so that the dose received is the maximum target and the dose received by healthy organs in the vicinity (organ at risk) is minimal. The purpose of this study was to determine the distribution of the absorption dose in liver cancer with radiation source γ 103 Pd using MCNPX. In this study the target organ used was liver (liver cancer). Organs at Risk in liver cancer are the right lung, kidney and pancreas. One way to simulate this is to use Monte Carlo N Particles eXtended (MCNPX). In this study used ¹⁰³Pd radioactive. the variation in the number of seeds used is from 10 to 70 seeds with an increase of 10. The ¹⁰³Pd activity used is 2x10⁻³Ci. The results of the MCNPX simulation show that the effective dose is directly proportional to the number of seeds used. Effective doses in the liver are 0.101 to 0.699 Sv. in the right lung 0.032 to 0.229 Sv. in the kidney 0.0005 to 0.0039 Sv and in the pancreas 0.0001 to 0.0149 Sv. If in the liver the percentage of effective dose is 100%.then the distribution of effective dose percentage in the right lung is 34.67%.kidney 0.63% and pancreas 1.06%. The percentage of the effective dose distribution is relatively safe because it is still below 75%.