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 radiation exposures from diagnostic medical examinations are generally low and are almost always justified by the benefits of accurate diagnosis of possible disease conditions. therefore, entrance skin dose (esd), body organ dose (bod), and effective dose (ed) from adult patients undergoing routine thorax posterior-anterior (pa) and thorax right lateral (rlat) were estimated in uni...

Parsons, J. L. and Townsend, L. W. Interplanetary Crew Dose Rates for the August 1972 Solar Particle Event. Using the coupled neutron-proton space radiation transport computer code (BRYNTRN), estimates of dose rates of protons in the skin, ocular lens and bone marrow, behind various thicknesses of aluminum shielding, for crews on space missions outside the Earth's magnetosphere, are made for th...

background: changes in body composition may be used for monitoring progression/ regression of a disease. prompt γ-rays in vivo neutron activation analysis (ivnaa) has been widely used for the measurement of body composition in recent years. objective: in this paper, we tried to improve the safety of ivnaa operator. methods: the most important factor for reducing the operator receiving dose is t...

gamma rays pose enough energy to remove electrons from atoms of absorbing material including human body and adversely affect human health. the external exposure of human beings to natural environmental gamma radiation normally exceeds that from all man-made sources combined. therefore, we monitored gamma dose rate in indoor environments and estimated corresponding annual effective dose in selec...

Enhanced cell lethality, also known as hyper-radiosensitivity, has been reported at low doses of radiation (≤0.5 Gy) in various cell lines, and is expected to be an effective cancer therapy. We conducted this study to examine the impact of time interval and dose rate of low-dose fractionated exposures with a short time interval. We evaluated the cell-survival rates of V79 and A549 cells using c...

background: pet/ct imaging using [18f]-fdg is utilized in clinical oncology for tumor detecting, staging and responding to therapy procedures. essential consideration must be taken for radiation staff due to high gamma radiation in pet/ct and cyclotron center. the aim of this study was to assess the staff exposure regarding whole body and organ dose and to evaluate environment dose in pet/ct an...

background: we have validated the monitor unit calculations from a commercially available treatment planning system (tps) for three intensity modulated radiotherapy (imrt) planning techniques for tangential breast irradiation by using ionization chamber measurements. materials and methods: treatment plans were generated for forty-two breast patients by a forward planned field in field technique...

I consider two issues concerning how to monitor global poverty for the Millennium Development Goals, the selection of poverty lines, and the data sources for monitoring poverty over time. I discuss the choice of a single international line, converted using purchasing power parity (PPP) exchange rates, versus the use of country-specific poverty lines. I note the difficulties in constructing PPP ...