PURPOSE The magnetic fields of linac-MR systems modify the path of contaminant electrons in photon beams, which alters patient skin dose. To accurately quantify the magnitude of changes in skin dose, the authors use Monte Carlo calculations that incorporate realistic 3D magnetic field models of longitudinal and transverse linac-MR systems. METHODS Finite element method (FEM) is used to genera...

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:  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 according to the international commission on radiological protection publication numbers 60 and 21, the environmental control standards should ensure human and other species protection to a desirable degree. since application of radiographic procedures in veterinary medicine has increased significantly, in this study, we aimed to evaluate the entrance skin dose to the animals (e.g....

Introduction:   Nowadays we are witnessing an exponential application of interventional radiology techniques in various communities as well as Iran. Radiological technique is regarded as  the  2nd  contributing  factor in  increasing  the  amount  of  public  doses  in various societies. So that related radiation protection organization has recommended measuring patient d...

background: one of the means of assessing dose to patients from computed tomography (ct) procedure is through the determination of the skin entrance dose (esd) with the appreciation of the concern that ocular exposure effects from ct scan includes possible induction of cancer and cataract. due to the relatively more recent introduction of ct scans, little work has been done in this area in the ...