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...

introduction wedge modifiers are commonly applied in external beam radiotherapy to change the dose distribution corresponding to the body contour and to obtain a uniform dose distribution within the target volume. since the radiation dose delivered to the target must be within ±5% of the prescribed dose, accurate dose calculation by a treatment planning system (tps) is important. the objective ...

context appropriate management of neonates, tested positive for congenital hypothyroidism (ch), in particular, the initial dosage of levothyroxine and the time of initiation of treatment is a critical issue. the aim of this study was to assess all current evidence available on the subject to ascertain the optimal initial dose and optimal initiation time of treatment for children with ch. eviden...

background: acrylamide (c3h5no) is a vinyl monomer. this water-soluble crystalline solid is a colorless, odorless agent which is used in scientific laboratories and some industries. acrylamide has cellular oxidative effects. acute or chronic poisoning with this agent happens as a result of skin, respiratory, or oral contacts. clinical manifestations depend on the dose, duration, and frequency o...

background: this work investigated the dosimetry limitations of the random and systematic uncertainties of sliding window (sw) intensity modulated radiation therapy (imrt). materials and methods: a varian 21ex linear accelerator, pinnacle3 treatment planning system and radiographic film dosimetry was used. the limitations of the sw were studied using beam modulation ranging from 2 to 100 mu/bea...

background: accelerated partial breast irradiation via interstitial balloon brachytherapy is a fast and effective treatment method for certain early stage breast cancers however skin, chest wall and lung doses are correlated with toxicity in patients treated with breast brachytherapy. objective: to investigate the percentage of the dose received by critical organ (skin), thermoluminescence dete...

objective: acute inflammatory demyelinating peripheral neuropathy (guillain-barre-syndrome) is by far the most common cause of immune-medicated peripheral nervous system disease in children; with the near disappearance of poliomyelitis, gbs is responsible for the great majority of cases of acute flaccid paralysis. so far, in several controlled studies, corticosteroids, plasmapheresis and ivig h...

background: it was intended to investigate the effect of physical wedge (pw) and enhanced dynamic wedges (edw) on contralateral breast dose during primary breast irradiation in radiotherapy treatment, using high energy photon beams. materials and methods: the varian’s clinac dual mode linear accelerator model 2100 c/d and siemen’s primus accelerators were used for radiation doses with 6 mv and ...

BACKGROUND Lead is a highly toxic and pervasive metal. Chronic exposure to low levels is responsible for significant health effects, particularly in children. Prevention remains the best option for reducing childhood lead exposure, however the knowledge, attitudes and practices to lead exposure in many developing countries is not known. METHODS We conducted four focus group discussions (FGD) ...