Relation to high absorption fraction of Tc sestamibi by kidneys in heart scan and these organs are near to generation organs (Ovaries and uterus). Urinary system (kidneys and urinary bladder) are specified as sources organs. The main object of this study is to determine the absorbed dose in these critical organs. we have set amount of absorbed fraction radiopharmaceutical in position of kidneys...

introduction: nasopharyngeal carcinoma is one of the most common malignancies in the head and neck region and radiotherapy is its treatment of choice. in spite of the fact that it is widely used, due to the presence of many sensitive organs or tissues in this region, patients may suffer from a wide range of side effects. one such sensitive tissue is the spinal cord. if the absorbed dose to spin...

The Monte Carlo simulations using the mathematical phantom of a human body model is useful as a method of getting to know the details of the radiation exposure in a human body. However, it is very difficult to evaluate experimentally the validity of the calculation result of the simulation using the human body model. Then, the mathematical phantom of voxel-type (voxel phantom) for the Monte Car...

introduction: orthogonal radial fields are those in which the central axes are perpendicular to each other. an example of these orthogonal fields is the set of craniospinal orthogonal fields that are used for radiotherapy of medulloblastoma. craniospinal radial fields consist of two parallel-opposed fields for brain exposure and one or two posterior spinal fields for spinal cord exposure. the m...

introduction radiotherapy is regarded as the first treatment of choice for nasopharyngeal carcinoma. despite the advantages of radiotherapy, patients may suffer from a wide range of side-effects due to the presence of many sensitive normal tissues in these regions. if the absorbed dose exceeds the tolerance level in parotid glands and the spinal cord, myelopathy, lhermitte's sign and xeros...

The purpose of this study is to quantify the discrepancy between optical guidance platform (OGP) frameless localization system (Varian) and Trilogy on-board imaging (OBI) system (Varian) for setting up phantom and stereotactic radiosurgery (SRS) patient; and to determine whether cone-beam CT (CBCT) is necessary for OGP patient setup, and compare CBCT and orthogonal kV-kV in term of their verifi...

Our institution delivers TBI using a modified Theratron 780 60Co unit. Due to limitations of our treatment planning system in calculating dose for this treatment, we have developed a fast Monte Carlo code to calculate dose distributions within the patient. The algorithm is written in C and uses voxel density information from CT images to calculate dose in heterogeneous media. To test the algori...

background: dose assessment using proper dosimeters is especially important in radiation protection optimization and imaging justification in diagnostic radiology. objective: the aim of this study is to obtain the entrance skin dose (esd) of patients undergoing lumbar spine imaging using two thermoluminescence dosimeters tld-100 (lif: mg, ti) and gr-200 (lif: mg, cu, p) and also to obtain the a...

background: broca’s and wernicke’s areas, which are important language areas of brain, are commonly irradiated in patients with right frontal lobe glioblastomamultiforme (gbm). we aimed to compare two different treatment planning techniques in terms of the doses in the broca’s and wernicke’s areas for the patients with right frontal gbm. materials and methods: two different treatment planning t...