tailieunhanh - Organ segmentation and absorbed dose calculation

The software of GAMOS version can read DICOM RTSTRUCT file to calculate the dose or energy deposited in a structure. Before being used, they have to be converted into the list of CT voxels that belong to each structure. One of the tools that can be used to draw structures on a CT image file is Carimas. | JOURNAL OF MEDICAL RESEARCH ORGAN SEGMENTATION AND ABSORBED DOSE CALCULATION Nguyen Thi Phuong Thao1 Nguyen Thien Trung2 1Vietnam Atomic Energy Institute 2Techbase-Yahoo Japan The software of GAMOS version can read DICOM RTSTRUCT file to calculate the dose or energy deposited in a structure. Before being used they have to be converted into the list of CT voxels that belong to each structure. One of the tools that can be used to draw structures on a CT image file is Carimas. We have developed a tool that could identify the CT voxels that belong to the structures drawn by Carimas and could write this information in a file usable by GAMOS. As a first check of the tool A geometrical comparison of the areas calculated with Carimas with those calculated by GAMOS using the converted file has been made. In a second step using a source of F -18 placed in the water volumes of the NEMA phantom and comparing the absorbed dose on a disintegration in the drawn structures calculated by Carimas with those calculated by GAMOS have been implemented. After validating the tool using the CT images of 5 adult male patients drawing in Carimas the structures defining several structures . kidney and spleen and calculating the self-absorbed and cross-absorbed dose with GAMOS were made. A patient to patient variability of up to spleen kidney was found. Keywords DICOM RTSTRUCT GAMOS Geant4 Carimas voxel phantom. I. INTRODUCTION The information on the anatomy the activity and the dose distributions in different parts of human body whether corresponding to real organs or to simulation issues is crucial for medical staff to determine the appropriate nuclear medicine or radiotherapy treatment as well as to understand the treatment effects. One of the tasks that need this information is the assessment of the possible side effects of internal exposure to radionuclide on the organs and tissues that strongly affect to the health of patients 1 . These features are imbedded and enable to