introduction: nowadays new radiochromic films have an essential role in radiotherapy dosimetry. properties such as high sensitivity, good reproducibility, high spatial resolution, easy readout and portability have made them attractive for dosimetry, especially in high-dose-gradient regions. material and methods: in this study, electron-beam dose distributions in homogenous and heterogeneous pha...

background: the aim of this work was to establish how well gel dosimeters performed, as substitutes for brain tissue compared with standard phantom materials such as water, polymethyl-methacrylate (or pmma), a150 plastic and te- liquid phantom material for dosimetry of neutron beams in boron neutron capture therapy. materials and methods: thermal neutron fluence, photon dose and epithermal neut...

UNLABELLED The biologic response of tissue exposed to radiation emitted by internal radioactivity is often correlated with the mean absorbed dose to a tissue element. However, studies show that even when the macroscopic absorbed dose to the tissue element is constant, the response of the cell population within the tissue element can vary significantly, depending on the distribution of radioacti...

Lung brachytherapy using high-dose rate (192)Ir technique is a well-established technique of radiation therapy. However, many commercial treatment planning systems do not have the ability to consider the inhomogeneity of lung in relation to normal tissue. Under such circumstances dose calculations for tissues and organs at risk close to the target are inaccurate. The purpose of the current stud...

background: people who have been administrated radiopharmaceuticals could be a source of radiation to their relatives, medical nurses, and people who are in contact with them. the aim of this work was to estimate radiation dose received by nuclear medicine nurses. materials and methods: in this study, the dose rates at various distances of 5 – 100 cm from 70 patients, who were administered diag...

introduction: in patients with thyroid carcinoma, radiation absorbed doses of the thyroid and surrounding tissues is important to weigh risk and benefit considerations. in nuclear medicine, the accuracy of absorbed dose of internally distributed radionuclides is estimated by different methods such as mird and direct method using tld. the aim of this study is using tld and a phantom to determine...

aflatoxins are toxins which are usually produced by a kind of aspergillus fungus named flavus, parasiticus, and numius. there are 18 kinds of aflatoxins have been discovered by scientists and aflatoxin b1 is the most toxic and carcinogenic. taking aflatoxins present in food causes lots of diseases like liver diseases, alcoholic liver, mutagenesis, and malformation in animals. it also has some o...

background: the assessment of rbe quantity in the treatment of cancer tumors with proton beams in treatment planning systems (tps) is of high significance. given the significance of the issue and the studies conducted in the literature, this quantity is fixed and is taken as equal to 1.1. objective: the main objective of this study was to assess rbe quantity of proton beams and their variations...

The work presents the results of the detailed analyses performed on the shielding capability of HCLL DEMO-type fusion reactor. The analysis is based on three-dimensional calculations with the Monte Carlo code MCNP-4C and consists in assessment of radiation loads to the super-conducting TF-coil at the inboard side of the reactor. A suitable 20-sector model of DEMO reactor, based on the reactor p...

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...