Calculation of absorbed dose rate in the esophagus, stomach and pancreas by the Mammosite applicator in breast cancer brachytherapy with MCNP

Introduction: Breast cancer is the most common cancer among women. Brachytherapy is one of the ways to treat breast cancer. In brachytherapy treatments, high-dose sources are used in interstitial placement. Here, Iridium-192 is used. Aim: modeling of a common breast cancer treatment applicator called MammoSite is done by the Monte Carlo simulation code. Then, calculate the absorbed dose in breast brachytherapy in the breasts, target volume (tumor) and organs including:esophagus, stomach and pancreas. Materials and Methods: The MCNPX code is the based on the Monte Carlo method. The code, with input file information and the use of the cross-section library,solves the problem and produces results in an output file. Results: when the breast is treated right, the absorbed dose in: esophagus=0/0115,stomach=0/00371,pancreas=0/0132,right breast=0/726,left breast=0/006,target volume=0/7Gy/min and when the breast is treated left, the absorbed dose in: esophagus=0/0123,stomach=0/0133,pancreas=0/0217,right breast=0/68,left breast=0/0104,target volume=0/7Gy/min. Conclusion: As expected, absorbed dose in the target volume and breasts specially the treated breast was the highest and after that the esophagus received the same significant dose.Depending on which breast is treated: esophagus, stomach and pancreas receive high doses based on the anatomy of the body. Mammosite appliator produces symmetry dose and can be dangerous,so it should be used with applicators that can produce asymmetry doses.

کلیدواژه ها:

brachytherapy ، mammosite ، breast ، esophagus ، stomach ، pancreas.