computed tomographyrepresents about 10% of all diagnostic radiology procedures, but it isresponsible for almost 50% - 60% of exposure from diagnostic procedures. inhead ct, other critical organs such as eye lenses and thyroids are in theradiation field. therefore, dose assessment in these organs is very important.the aim of this study is to estimate the absorbed dose in critical organs ofpatien...

background: the shielding methods in radiotherapy due to delivering an accurate radiation dose to cancer tissues and avoiding unnecessary dose to normal tissues are very important. these methods include lead standard blocks, individual molding and multi leaf collimator (mlc). the mlc method is not still common in iran radiotherapy centers. individual molding is better than the lead block shield...

background: natural background radiation of a particular region is one of the distinctive factors defining the status of environment. eloor island is an industrial area in ernakulum district of the state of kerala, india. the indoor and outdoor gamma level measurements have been carried out for the region for evaluating the annual effective dose to the population residing in this area. material...

introduction:  skin  sparing  is  one  of  the  most  desirable  characteristics  of  high  energy  photon  beams. however, the photons emerging from the target of linacs are contaminated by secondary  electrons  as  a  result  of  their  interactions  with  air,  collimators,  flattening  filter  and  any  other  objects in their path. this phenomenon tends to increase the skin dose received b...

introduction: the aim of present study was to estimate effective dose from most common procedures performed in nuclear medicine departments of golestan province. methods: data of nuclear medicine procedures performed in 2 nuclear medicine departments in golestan province were collected during 4 years. effective dose, collective effective dose and effective dose per examination were calculated u...

background: in vivo dosimetry is a method for estimation of overall error in the delivered dose to the patients at the end of radiotherapy process. in this research, two methods for target dose calculation were evaluated on midline and central axis of photon beams in in vivo dosimetry of thorax fields. materials and methods: entrance and exit doses for anterior and lateral fields of thorax were...

introduction: esophageal cancer is one of the most frequently occurring cancers in iran and having a  high  incidence  rate  among  other  countries.  radiotherapy  is  one  of  the  three  methods  (surgery,  radiotherapy and chemotherapy) for radical or palliative treatment of esophageal cancer. in this method  of treatment, the organs such as heart and spinal cord are regarded as organs at r...