فهرست مطالب

  • Volume:8 Issue: 1, 2010
  • تاریخ انتشار: 1389/03/26
  • تعداد عناوین: 10
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  • Dr. H. Mozdarani Page 1
    The Iranian Journal of Radiation Research (IJRR) is now in the eighth year of publication. This journal is the mouth piece of shared idea of Dr Shahram Akhlaghpoor and me, which was established way back in 2002. At that time the main emphasis of the founder members was to make the subject of radiation research attractive and interesting especially for combating cancer and risk assessment. The dream for creating the Journal has come true by the help of Dr Seyed Mahmood Aghamiri who obtained the necessary permission for its publication and the Novin Medical Radiation Institute for financial and logistic supports. Our mission has been to serve the needs of scientists and community by working with capable researchers and professionals from across the world to produce the most accurate and up to date scientific and technical resources. From summer 2003 when the first issue of IJRR was published, IJRR was devoted to the rapid publication of fundamental research papers on all aspects of Radiation Research. All contributions were rigorously refereed and selected on the basis of quality and originality of the work as well as the breadth of interest to readers. Although for understanding reasons the authors were reluctant to publish their articles in the journal. From publication of the first issue, I, as the editor-in-chief with the help of all my colleagues, have tried to improve the quality and responsibility of the journal and its articles over the past years. Through this continued efforts we could index the journal with a host of indexing agencies and we are expecting to get higher impact factor for journal in a near future. Thus IJRR has now gained an international reputation and a strong emphasis on high academic standards. In addition to authors from Iran who contributed to IJRR, I should thank all the authors across the globe that helped us by submitting articles to this journal. I would like to thank to our editorial board for their help and suggestions, all reviewers for their sincere help and careful review of the articles and my colleagues at the editorial and publishing office. Also I express my special thanks and gratitude''s to Dr Shahram Akhlaghpoor and his honorable colleagues at the Novin Medical Radiation Institute for their continued logistic and financial support to keep the journal alive; and to Miranda Firouzbakhsh and Sohail Mozdarani for their tired less efforts at the editorial office to manage the articles from the first day of receipt until publication. Seven years is not a long time to assess a journal''s worth. However, 7 years is also ample time when we should have been able to promote the journal to a greater height. Thus let us not to miss this opportunity now. The Iranian Journal of Radiation Research is now indexed in ISI, Scopus, Index Copernicus, EM base and etc, therefore, there should be no hesitation for researchers to put their valuable works in the journal and work for the journal to become more visible internationally. Young scientists are requested to contribute by submitting interesting observations, raising controversies and publish constructive criticisms on published articles as well as submitting original articles in the cutting edge areas of the radiation science. I request all the scientists and researchers in the field of radiation science to visit the journal website at www.ijrr.com. Apart from free access to abstracts and full text articles in PDF format, each article has its individual statistics of utility. You can see how often the website has been visited, how often articles in the journal have been visited and how often the PDF article has been downloaded. The impact factor and citations are two important indices for any journal and an individual article''s utility. IJRR has now published enough papers in different fields of radiation research to be cited by authors in their forthcoming articles. However, I hope in the future, the number of times an article has been visited or PDF downloaded will also be used to understand the interest in a particular article by readers who do not publish articles. Visit and download of some articles published in IJRR is incredible. There are papers visited nearly 4000 times and downloaded more than 1300 times. These statistics and being indexed by main indexing agencies indicate the level of articles published in IJRR and its scientific importance in the short life of this journal. I am sure with all your help this journal will be able to immortalize itself.
  • A. Chakrawarti, Dr. R.K. Purohit, M. Agarwal, P. Joshi, A. Basu, K.M. Bhartiya, A. Bhardwaj Page 3
    Background
    Protective effect of Emblica against radiation and cadmium induced biochemical changes in mouse kidney has been studied.
    Materials And Methods
    Adult male mice were divided into seven groups: I (shamirradiated), II (cadmium chloride), III (irradiated with 2 Gy gamma rays), IV (radiation and cadmium chloride), V (Cadmium chloride and Emblica), VI (radiation and Emblica), VII (radiation, cadmium chloride and Emblica). The animals were autopsied after 1-28 days of treatment. The kidney was taken out and different biochemical parameters such as total proteins, glycogen, cholesterol, acid phosphatase activity, alkaline phosphatase activity, DNA and RNA were estimated.
    Results
    The value of glycogen, RNA, acid phosphatase and alkaline phosphatase activity increased up to day-14 in non drug treated groups and day-7 in the Emblica treated groups and thereafter decreased up to the last autopsy interval. The value of cholesterol and DNA decreased up to day-14 in non drug treated groups and day 7 in the drug treated groups then increased in all the groups. In groups III, IV, VI and VII the value of total proteins increased during early intervals and decreased thereafter, but the animals of groups II and V, which were given only cadmium chloride with or without Emblica, showed an opposite trend. The biochemical parameters showed highly significant values (p<0.001) as compared to normal ones.
    Conclusion
    Results indicated that combined treatment of radiation and cadmium chloride exerts synergistic effect. The drug treated animals showed less severe biochemical changes and an early and fast recovery, which may be due to protection provided by Emblica.
  • Dr. S.M.J. Mortazavi, M.A. Mosleh, Shirazi, M. Baradaran, Ghahfarokhi, Z. Siavashpour, A. Farshadi, M. Ghafoori, A. Shahvar Page 11
    Background
    Biological shielding of nuclear reactors has always been a great concern and decreasing the complexity and expense of these installations is of great interest. In this study, we used datolite and galena (DaGa) minerals for production of a high performance heavy concrete.
    Materials And Methods
    Datolite and galena minerals which can be found in many parts of Iran were used in the concrete mix design. To measure the gamma radiation attenuation of the DaGa concrete samples, they were exposed to both narrow and wide beams of gamma rays emitted from a cobalt-60 radiotherapy unit. An Am-Be neutron source was used for assessing the shielding properties of the samples against neutrons. To test the compression strengths, both types of concrete mixes (DaGa and ordinary concrete) were investigated.
    Results
    The concrete samples had a density of 4420-4650 kg/m3 compared to that of ordinary concrete (2300-2500 kg/m3) or barite highdensity concrete (up to 3500 kg/m3). The measured half value layer thickness of the DaGa concrete samples for cobalt-60 gamma rays was much less than that of ordinary concrete (2.56 cm compared to 6.0 cm). Furthermore, the galena concrete samples had a significantly higher compressive strength as well as 20% more neutron absorption.
    Conclusion
    The DaGa concrete samples showed good shielding/ engineering properties in comparison with other reported samples made, using high-density materials other than depleted uranium. It is also more economic than the high-density concretes. DaGa concrete may be a suitable option for shielding nuclear reactors and megavoltage radiotherapy rooms.
  • Dr. M.N. Salihin Yusoff, A. Zakaria Page 17
    Background
    We investigated whether the lungheart ratio parameter (LHR) can be used to identify the optimum cut off frequency for Butterworth filter in 99mTc myocardial SPECT imaging.
    Materials And Methods
    This study involved a cardiac phantom system consisting of cardiac insert in which 1.10 cm cold defect was inserted into its myocardium wall and filled with 4.0 μCi/ml (0.148 MBq/ml) 99mTc concentration. The cardiac insert was then put into a cylindrical tank which filled with six different 99mTc concentrations as background. Thus, six target background concentrations ratios (T/B) were carried out. The LHR was determined for every SPECT raw image obtained corresponding to each T/B. Then, 130 different combinations of filter parameters from Butterworth filter were utilized to reconstruct each SPECT raw image. The determination of count in myocardium, background, and defect regions of interest (ROI) were performed for every reconstructed image. All the count values were then used to calculate contrast, signal-to-noise ratio (SNR), and defect size. Each criterion was graded (1 to 100) and then summed together to obtain total grade. The optimum cut off frequency for each LHR was determined from the total grade. The relation between optimum cut off frequency for Butterworth filter and LHR was established using linear regression.
    Results
    There were good relationship between the optimum Butterworth cut off frequency and LHR (R2 = 0.864, p < 0.01). The optimal cut off frequency correspond to the change in LHR can be expressed by the equation: Optimum cut off frequency = 0.715*LHR + 0.227.
    Conclusion
    This study suggests that the optimum cut off frequency for Butterworth filter should be determined by referring to LHR in each patient study.
  • S.S. Seyyedi, Dr. H. Mozdarani, M. Rezaei Tavirani, S. Heydari Page 25
    Background
    Rapidly increasing possibilities of exposure to environmental extremely low-frequency electromagnetic fields (ELF-EMF) have become a topic of worldwide investigation. Epidemiological and laboratory studies suggest that exposure to ELF-EMF may increase cancer risk therefore assessment of chromosomal damage in various cell lines might be of predictive value for future risk estimation.
    Materials And Methods
    Primary cultures of fibroblasts from human skin biopsy were exposed to continuous extremely low-frequency electromagnetic fields (3, 50 and 60 Hz, sinusoidal, 3h, and 4 mT). Also immortalized cell lines, SW480, MCF-7 and 1321N1 were exposed to continuous ELF-EMF (50 Hz, sinusoidal, 3 h, 4 mT). Metaphase plates were prepared according to standard methods and stained in 5% Giemsa solution. Chromosomal aberrations of both chromosome and chromatid types were scored to evaluate the effects of ELF-EMF on primary or established cell lines.
    Results
    Results indicate that by increasing the frequency of ELF-EMF, chromosomal aberrations were increased up to 7-fold above background levels in primary human fibroblast cells. In addition, continuous exposure to a 50 Hz electromagnetic field led to a significant increase in chromosomal aberrations in SW480, MCF-7 and 1321N1 cell lines compared to sham control.
    Conclusion
    Results obtained indicate that ELF-EMF has the potential for induction of chromosomal aberrations in all cell types.
  • M. Momennezhad, Dr. S.R. Zakavi, R. Sadeghi Page 31
    Background
    99mTc is a widely used radioisotope in nuclear medicine centers which is obtained by elution from Mo-99/Tc-99m generators. Usually the generators are either supplied by the Iran Atomic Energy Agency or by private companies from foreign countries. In this study we have measured 99Mo contamination in 99mTc elute from different generators in a period of one year.
    Materials And Methods
    The radionuclide impurity of the 99mTc elute were studied in two types of radionuclide generators (A: produced in Iran and B: Imported from other country). In-vitro measurements were performed using dose calibrator. Direct measurements were made, using a standard canister at the time of milking of the generators and also in subsequent hours after milking.
    Results
    The results showed a mean of 99Mo impurity in generators A and B to be 0.00932±0.0043 and 0.0170±0.0127 respectively. Although the results showed that the 99Mo contamination in 99mTc elute was lesser than the maximum accepted activity limit of 0.015%, the difference in these two types may reflect different methods of productions of generator, as well as the quality control procedures.
    Conclusion
    The mean of 99Mo contamination in generators produced in Iran Atomic Energy Organization was lesser than generators imported from foreign origin.
  • H. Arabi, Dr. A.R. Kamali Asl, S.M. Aghamiri Page 37
    Background
    A variable resolution X-ray (VRX) CT scanner provides a great increase in the spatial resolution. In VRX CT scanners, the spatial resolution of the system and its field of view (FOV) can be changed according to the object size. One of the main factors that limit the spatial resolution of VRX CT scanner is the effect of the X-ray focal spot.
    Materials And Methods
    A theoretical study of the effect of X-ray focal spot on the spatial resolution of VRX CT is presented in this paper. In this study, we used the parameters of an actual VRX CT scanner. By using the relevant equations, the effects of foal spot sizes of 0.6 and 0.1 mm were calculated on spatial resolution of the system at various opening half angles.
    Results
    Focal spot size of 0.6 mm had no significant effect on spatial resolution of the system for opening half angles of above 14°. Even focal spot sizes of larger than 0.6 mm could not affect the spatial resolution of the system. For opening half angles of below 14°, foal spot size of 0.6 mm limited the spatial resolution of the system to 5.7 cycle/mm and caused great spatial resolution non-uniformity along the detector length.
    Conclusion
    By focal spot size of 0.1 mm, the spatial resolution varied as a function of the opening half angle and increased to more than 30 cycle/mm. Additionally, focal spot size of 0.1 mm minimized the spatial resolution non-uniformity along the detector length.
  • Dr. A.A. Mowlavi, A. Afzali, N. Afzali Page 45
    Background
    Skin cancer can be treated by various methods. Electron radiotherapy has been a useful therapeutic modality in the treatment of skin cancers in areas which are difficult to cure by other methods. Depth dose distribution of 166Ho using VARSKIN2 code is presented in this work.
    Material And Methods
    Depth dose distribution of 166Ho was calculated, using VARSKIN2 code by adding of 166Ho data to the library of VARSKIN2 code. After adding 166Ho radionuclide data to the library of the code, it was run for various input parameters including: density, air gap thickness, radiation time and different source geometry. Different forms of sources which have been used in this research are 2-D disk, cylindrical and spherical shapes.
    Results
    The result showed that the skin absorbed depth dose variation was an exponential function because of short range of beta ray. Dose gradient was very high near the sources. For the same activity, disk source induced a dose more than spherical and cylindrical source to skin surface.
    Conclusion
    Superficial skin tumors could be successfully treated by topical application of beta-emitting 166Ho source. VARSKIN2 is a fast, accurate and user friendly code for beta dosimetry and can be used for dose optimization calculation, especially in beta source over the human skin.
  • A. Esk, Arlou, Mr. K. Ghazi, Khanlou Sani, A.R. Mehdizadeh Page 51
    Background
    In recent decades many guidelines has been conducted by radiation protection organizations about radiation protection in dentistry. This study aimed to evaluate the observance of these guidelines in educational clinics of all dental schools in Iran.
    Material And Methods
    In this cross-sectional study a self-administered questionnaire, based on National Radiation Protection Board (NRPB) and European Commission guidelines, was conducted. The radiology departments of all dental school (18 schools) were surveyed in this study. The questionnaire was consisted of 3 sections including intraoral radiography, extraoral radiography and implementation of quality control programs.
    Results
    In the case of the existence of radiation protection facilities (such as lead apron, thyroid shield and lead impacted walls) the use of high speed films and existence of automatic processor in dental schools, there was a proper condition. The main problem was related to lack of regular quality control and quality assurance programs. Digital radiography systems were employed in none of the schools and it was occasionally used for research purposes at some of them.
    Conclusions
    This study has emphasized on the need for further consideration of radiation protection principles in dental schools, especially on the field of quality control and quality assurance programs. Iran.
  • Prof. V. Wiwanitkit Page 59
    Editor, I read the recent publication by Toossi et al. with a great interest (1). Toossi et al. concluded that “Average gonad and bone marrow doses for North Khorasan, Boshehr and Hormozgan provinces were less than the corresponding values for normal area (2).” There are some facts on this report to be concerned. I agree that the detected levels might be high in the mentioned area, but the problem is whether this high dosage is an actual problematic phenomenon. First, the selection on small sites and samplings within a short period might not provide a good representative data on the actual situation in that area. Second, the difference in time of sample collection among different sites might contribute to difference in detected levels. The variation of the atmosphere might be a big factor to be mentioned. Third, the detected levels might not directly imply the risk for the people living in those areas since the people do not statically but dynamically lives from places to places. References: 1. Toossi MTB, Bayani SH, Yarahmadi M, Aghamir A, Jomehzadeh A, Parast MH, Tamjidi A (2009) Gonad, bone marrow and effective dose to the population of more than 90 towns and cities of Iran, arising from environmental gamma radiation. Iran J Radiat Res, 7 (1): 41- 47. 2. Nelson GA (2003) Fundamental space radiobiology. Gravit Space Biol Bull, 16 (2): 29- 36. N.B.: This comment has been sent to the corresponding author for reply. However, so far we did not receive any reply from the authors. We will post the reply from the authors in forthcoming issue of IJRR if received.