background: radioiodine therapy has proven to be an effective method in the treatment of patients with differentiated thyroid carcinoma after thyroidectomy. the scope of this study is to describe a method to obtain the dose of organs using medical internal radiation dosimetry (mird) method. at the end, the results of mird calculations were compared with thermoluminescent dosimeter (tld-100). ma...

Slabs of natural and depleted uranium are used routinely to calibrate personal dosimeters and radiation survey instruments for beta radiation. However, little information is available on the absorbed dose rate produced by a uranium slab as a function of depth in matter. In this study, an extrapolation chamber was used to measure the dose rate produced by natural uranium at a variety of depths i...

Introduction: Cancer is, in essence, a genetic disease and is the second leading cause of death globally. Fortunately, many common types of cancer are treatable if detected early and of course there are many medications and treatments available today. Among the new methods to treat cancer, radiotherapy seems to be hopeful in patients with malignancies. This work investigates th...

background: the electron contamination may reduce or even diminish the skin sparing property of the megavoltage beam. the detailed characteristics of contaminant electrons are presented for different field sizes and cases. materials and methods: the monte carlo code, mcnpx, has been used to simulate 18 mv photon beam from a varian linac-2300 accelerator. all dose measurements were carried out u...

The Hong Kong Observatory has been continuously monitoring the environmental gamma absorbed dose rates in the air in Hong Kong since the late 1980’s. Spatial and seasonal variations in the environmental gamma absorbed dose rate in the air in Hong Kong have been evaluated. The spatial variations are found to be related to the variation in the geological structure across the territory and the sea...

The paper describes dosimetric models that allow the estimation of average radiation exposures to terrestrial biota due to environmental sources in the soil as well as internal uniform distributions of radionuclides. Simple three-dimensional phantoms for 13 faunal reference organisms are specified. The calculation of absorbed dose per unit source strength for these targets is based on photon an...

High dose rate brachytherapy (HDR) using 192Ir sources is well accepted as an important treatment option and thus requires an accurate dosimetry standard. However, a dosimetry standard for the direct measurement of the absolute dose to water for this particular source type is currently not available. An improved standard for the absorbed dose to water based on Fricke dosimetry of HDR 192Ir brac...

Background: A new biological dosimeter based on methemoglobin level was developed in this study. Materials and Methods: Methemoglobin level in erythrocytes from mice subjected to &gamma rays from a 60Co source was detected using the methemoglobin kit. The dose range was from 0.5 to 8 Gy and the dose rate was 0.5 Gy/min. Results: The results demonstrate that methemoglobin level increases with in...