introduction: clinical application of encapsulated radioactive brachytherapy sources has a major role in cancer treatment. in the present research, the effects of different tissue densities on the dose distribution of a 103pd brachytherapy source in a spherical phantom of 50 cm radius have been studied. material and methods: as is well known, absorbed dose in tissue depends to its density, but ...

Introduction: In brachytherapy treatments, high-dose sources are used in interstitial placement. In this paper, the modeling of a common breast cancer treatment applicator called MammoSite is done by the Monte Carlo simulation code. Then, to study and calculate the amount of doses in the breast and the dose rate of the organs at risk of radiation, including: lungs, ribs and ski...

background: natural radioactivity in materials under certain conditions can reach the hazardous radiological levels. so, it becomes necessary to study the natural radioactivity in different materials to assess the dose for the population in order to know the health risks and to have a baseline for future changes in the environmental radioactivity due to human activities. materials and methods: ...

introduction: skin dose and depth dose distribution of some beta sources that can contaminate skin or protective clothing covering the skin have been calculated using varskin2. materials and methods: in this research, absorbed dose to skin and depth dose from the skin surface have been calculated for 90sr/90y, 147pm, 32p beta emitter radioisotopes by using input parameters: activity of source, ...

introduction evaluation of the delivered dose of externally wedged photon beams by external diode dosimeters during the treatment process requires the estimation of exit surface dose correction factors in various wedge angles and field sizes. materials and methods a system of absorbed dose evaluation, using p-type diode dosimeters placed on the exit surface of a phantom, was characterized for e...

to improve the accuracy of the activity quantification and the image quality in scintigraphy, scatter correction is a vital procedure. the aim of this study is to compare the accuracy in calculation of absorbed dose to patients following bone scan with 99m tc-marked diphosphonates ( 99m tc-mdp) by two different methods of background correction in conjugate view method. this study involved 22 pa...

background: the equivalent dose in the human body due to the natural gamma-emitting radionucides (238u, 232th and 40k) in the surface soil surrounding the consolidated tin mine site in bukuru-jos, nigeria has been determined in this study. materials and methods: measurements of the soil natural radioactivity were made using a multi-channel pulseheight analyzer (canberra series 10 plus) coupled ...

In this paper an attempt is made to formulate criteria for the accuracy in the delivery of absorbed dose to a patient during photon or neutron therapy. These requirements are mainly based on the relative steepness of dose-effect curves for local tumour control and normal tissue damage. A review of these dose-effect curves after photon irradiation shows a great variety in steepness; the curves f...

introduction radon is a colorless and tasteless gas which exists in most soils. it is a substance that poses a potential risk for lung cancer in case a person is exposed to high levels over long periods of time. the environmental protection agency (epa) estimates that 90% of lung cancers per year are caused by radon. the aim of this paper is to estimate the absorbed doses of 222rn by mcnpx simu...