عنوان مقاله [English]
نویسنده [English]چکیده [English]
During radiotherapy by any radiation, it is always essential to stop absorbing the excess dose by a tissue. To better treat cancerous tissues and to make more precise irradiation for a cancerous tumor, there needs the accurate irradiation time to be estimated. First, the constituent materials of any of the existing organs in abdominal tissue are extracted and defined in the MCNPX code. Then, every organ in the abdominal tissue is voxelized by MATLAB software. Each of the voxels is defined based on Hounsfield unit of pixels in DICOM images. Then, the voxels are assigned to the related tissue which is comprised of its constituent materials, and they are filled up with them. Then, the liver tissue is segmented among the abdomen region from other tissues. Then, the geometry of the segmented liver tissue is generated as input data for MCNPX code, and the absorbed dose is computed. After obtaining the values of absorbed doses in liver tissue per each of incident fast neutron energies, the required irradiation time is obtained in second by making an appropriate proportion of absorbed dose and activity. This precise required irradiation time is obtained by an advanced software application (designed in this research using Delphi 7 programming language) through establishing a relationship between the absorbed dose and activity based upon the energy of clinical fast neutron source. The required irradiation time is calculated to reach the desired dose for each patient during fast neutron radiation therapy for similar liver tissues accordingly.