background: the anatomic position and proven radiosensitivity of the thyroid make it an organ of concern in dental x-ray examinations. a national radiation protection department (nrpd)-sponsored pilot study carried out in the dental radiology department of rums., to assess if the radiation dose in panoramic radiographies could be reduced without significant impairment of the subjective image qu...

background: ionizing radiation is present in all environment of the earth’s surface, beneath the earth and in the atmosphere. human beings are exposed to external radiation from their surroundings naturally and also to internal radiation from food, water and air they consume. then, it is important to measure and develop knowledge about radiation. objective: this study is designed to evaluate th...

introduction : methotrexate (mtx) is an anti folate drug that used in malignant and non malignant patients. the usage of high dose methotrexate was limited to patients with: osteogenic sarcoma, ewing sarcoma and lymphoma. the aim this study was to determine the toxicity or side effects of very high dose methotrexate (8-10 gr/m 2 /cycle). this study is the first study in iranian patients and one...

introduction:  on  the  basis  of  percent  depth  dose  (pdd)  calculation,  the  application  of  dosimetry  in  radiotherapy  has  an  important  role  to  play  in  reducing  the  chance  of  tumor  recurrence. the aim of this study is to introduce a new formula for calculating the centeral axis  percent depth doses of cobalt-60 beam.   materials and methods: in the present study, based on ...

background: in neutron interaction with matter and reduction of neutron energy due to multiple scatterings to the thermal energy range, increasing the probability of thermal neutron capture by neutron captures makes dose enhancement in the tumors loaded with these materials.   objective: the purpose of this study is to evaluate dose distribution in the presence of  10 b ,  157 gd  and  33 s  ne...

background: 3dcrt (three-dimensional conformal radiotherapy) and imrt (intensity-modulated radiotherapy) has provided us with tools to delineate the radiation dose distribution of tumor targets. however, the precision of radiation can be compromised by respiratory motion, which usually limits the geometric and dosimetric accuracy of radiotherapy. the purpose of this study is to evaluate the imp...

background: it is considered that if radon gas is inhaled and ingested, it is the primary health risks for lung and stomach cancers. this paper presents the measurement results of radon activity concentrations both residential tap water and dam water for kastamonu city centre-turkey. materials and methods: the radon activity concentrations of water samples collected from 60 tap waters at four l...

conclusions atorvastatin may play a protective role in pulmonary fibrosis, with its effects mediated via the station’s antioxidant and anti-inflammatory properties. atorvastatin may be a potential agent for the treatment of lung injury and fibrosis. background pulmonary fibrosis is an idiopathic and chronic inflammatory interstitial lung disease, with a negligible response to available medical t...

conclusion we constructed and validated a ct colonography phantom with correct density allowing performance of reproducible experiments. materials and methods we found 15 different phantom designs by literature search and compared their advantages and disadvantages based on their description and images. we tested various materials for density and mechanical properties and constructed a phantom ...

background; environmental gamma ray refers to the gamma radiation from terrestrial sources and building materials. in enclosed spaces radiation can become a health hazard leading to potential increase in the rates of lung cancer. the goal of this study is to assess the exposure to natural gamma radiation of children in the schools of zanjan province. method; the natural gamma radiation was asse...