Background and Objective: Professional radiation workers are occupationally exposed to long-term low levels of ionizing radiation. Occupational health hazards from radiation exposure, in a large occupational segment of the population, are of special concern. Biological dosimetry can be performed in addition to physical dosimetry with the aim of individual dose assessment and biological effects....

apoptosis, a physiologic mechanism to eliminate unwanted cells, is also induced by ionizing irradiation, through production of free radicals. it has been demonstrated that antioxidants such as vitamin e are able to protect cells from damage caused by free radicals. taken together we found it reasonable to make an attempt to evaluate the protective effect of vitamin e against apoptosis. the irra...

The “Linear No Threshold” hypothesis, used in all radiation protection practices, assumes that all doses, no matter how low, increase risk. However, in human and other mammalian cells, low doses of low LET radiation such as gamma and X-rays induce an adaptive response that protects against both radiation-induced and spontaneous risk. An in vivo test of the hypothesis in mice showed that a 100-m...

background: providing a cross-sectional image is essential for preimplant assessments. computed tomography (ct) and cone beam ct (cbct) images are very expensive and provide high radiation dose. tangential projection is a very simple, available, and low-dose technique that can be used in the anterior portion of mandible. the purpose of this study was to evaluate the accuracy of tangential proje...

Background: Given the importance of scattered and low doses in secondary cancer caused by radiation treatment, the point dose of critical organs, which were not subjected to radiation treatment in breast cancer radiotherapy, was measured.Objective: The purpose of this study is to evaluate the peripheral dose in two techniques of breast cancer radiotherapy with two energies. Methods: Eight diff...

the cancer of oral cavity is related to lesions of mucous membrane of tongue and gum that can be treated with radiation therapy. a lateral photon field can be used to treat this kind of tumor, which has a side‑effect on normal tissue in the opposite side of the oral cavity. in this study the dosimetric effect of the various shields in oral cavity is evaluated. in this study, a special phantom s...

The prime concern of radiation protection policy since 1959 has been to protect DNA from damage. In 1994 the United Nations Scientific Community on the Effects of Atomic Radiation focused on biosystem response to radiation with its report Adaptive Responses to Radiation of Cells and Organisms. The 1995 National Council on Radiation Protection and Measurements report Principles and Application o...