Background: Cardiac catheterization plays an essential role in the evaluation of suspected heart failure patients. This work aimed to determine the mean effective dose of patients undergoing catheterization tests and to estimate the associated radiation risk of malignancy. Material and Methods: Measurements were performed during 65 coronary angiographies (CA), 70 coronary angioplasties (PTCA) 27, radio fluoroscopy (RF) ablations and 25 electro physiologies procedures in a dedicated laboratory. The procedures were undertaken with the Siemens and General Electric X-ray equipment. A dose area product (DAP) meter was also used. The DAP values and fluoroscopy times were recorded for each patient. Results: The mean DAP values and patient effective doses were 19. 53 Gy. cm2 and 1. 71 mSv for CA, 49. 74 Gy. cm2 and 4. 57 mSv for PTCA, 153. 34 Gy. cm2 and 16. 38 mSv for ablations and 14. 88 Gy. cm2 and 1. 65 mSv for electrophysiology, respectively. The patient radiation risk was estimated at 13, 1. 3, 1. 3, 3. 6 fatal cancer per 10000 procedures of ablations, electrophysiology, CA and PTCA cases, respectively. Conclusion: Results showed that the radiation risk due to RF cardiac ablation is higher than the other complication procedures so, efforts should be made to minimize patient radiation risk from RF ablation procedures. Also we found no clear correlation between cardiologist level of experience and reduced level of patient,s dose.

Introduction: Internal radiation dosimetry is important from a radiation protection point of view and can help to optimize the radiation dose delivered to the workers, public, and patients. It has a rather simple protocol but needs a large amount of data. Therefore, it is difficult to do on a routine basis. The use of computer programs makes internal radiation dosimetry simpler and less time consuming and also decreases the possibility of human errors. Methods: The photon’ s specific absorbed fractions for two versions of Oak Ridge National Laboratory phantoms were calculated using MCNPX code and a Python code was used to calculate the S-values for selected radionuclides. Then calculated S-values transferred to an excel spreadsheet. The program’ s GUI was developed with the Tkinter module of Python programming language. Results: A user-friendly program for internal radiation dosimetry was developed using Python programming language. This program allows the user to calculate the absorbed dose for 20 source organs in 23 target organs for two phantoms. Also, it is possible to compare the results of the two phantoms. Originally, 40 radionuclides were included in the program. Conclusion: This program can be a useful tool for the assessment of organ absorbed doses for individuals dealing with radiation such as patients and workers. It decreases the time of dose calculation and helps to avoid human mistakes.

Introduction: In the present work, the steps of constructing hybrid phantoms have been studied. Mathematical and voxel phantoms are two various kinds of computational human body models which used in dose evaluations and estimations. In mathematical phantoms, organs contour define with mathematical equations and therefore they are not realistic, unlike voxel phantoms are image-based and more real. In turn, the disadvantage of voxel phantoms is extreme dependence of organs contour on CT and MRI image contrast. Hybrid phantoms are more realistic than mathematical phantoms and more desirable than voxel phantoms due to their flexibility in the shape and size of organs. In this approach, organs surface is defined with nonuniform rational B-spline (NURBS) surface which is a mathematical technique used in 3D graphics and animations extensively.Methods: Three steps are carried out to generate a hybrid phantom. (1) Transforming 2D images of human body to 3D model (2) Producing a 3D polygon mesh model of human body and internal organs (3) Creating NURBS. Initially, CT and MRI images for identifying soft and hard tissues are used. Then, two first steps can be constructing with software codes such as 3D-Doctor. For third step, NURBS modeling software can be used such as Rhinoceros.Results: We constructed hybrid phantoms with real CT and MRI images and the result is the Rhinoceros normal outcome file as *.rhp. It can be used for any size of human body because the size of organs is changeable. This pliability is the effect of NURBS control points which is the most important advantage of hybrid phantoms.Conclusion: We used advantages of both mathematical and voxel phantoms in constructing hybrid phantoms and thus they have the desirable shape and flexibility in organs. We should transform this phantom to voxel for applying in Monte carlo codes (MCNP). This voxelisation could be performing with MATLAB codes.Furthermore heart and respiratory motions can be simulated with this technique in 4D phantoms.

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.Methods: In this biodosimetry study, some hematological parameters have been examined in 40 exposed and 40 control subjects who were matched by gender, age and occupational records (±3 years) in Kermanshah hospitals in Iran (2013-2014).The occupational radiation dose was measured by personal dosimetry device (film badges). The data was analyzed using SPSS V.20 and statistical tests such as two-sided Student’s t-test.Results: Exposed subjects had a median exposure of 0.68±1.58 mSv/year by film badge dosimetry. radiation workers with at least a 10-year record showed lower values of Mean Hemoglobin (Hb) and Mean Corpuscular Volume (MCV) compared to the control group (p<0.05). The mean value of Red Blood Cells (RBCs) in personnel working in Radiology departments seemed to show decrease in comparison with other radiation workers.Conclusion: Although the radiation absorbed doses were below the permissible limits based on the ICRP, this study showed the role of low-level chronic exposure in decreasing Hb and MCV in the blood of radiation workers with at least 10 years records. Therefore, the findings from the present study suggest that monitoring of hematological parameters of radiation workers can be useful as biological dosimeter, and also the exposed medical personnel should carefully follow the radiation protection instructions and radiation exposure should be minimized as possible.

Background: Panoramic imaging is one of the most common imaging methods in dentistry. Regarding the side-effects of ionizing radiation, it is necessary to survey different aspects and details of panoramic imaging. In this study, we compared the absorbed x-ray dose around two panoramic x-ray units: PM 2002 CC Proline (Planmeca, Helsinki, Finland) and Cranex Tome (Soredex, Helsinki, Finland). Materials and Methods: In this cross-sectional study, 15 thermoluminescet dosemeters (TLD-100) were placed in 3 semi-circles of 40cm, 80cm and 120cm radii in order to estimate x-ray dose. Around each unit, the number of TLDs in each semicircle was 5 with equal intervals. The center of semicircles accords with the patient’ s position. Each TLD was exposed 40 times. These dosemeters were read out with a Harshaw Model 4000 TLD Reader (USA). The calibration processing and the reading of dosemeters were performed by the Atomic Energy Organization of Iran. Results: The mean absorbed dose in three lines of PM 2002 CC Proline was 123. 2± 15. 1, 118. 0± 11. 0 and 108. 0± 9. 1 μ Sv, (p=0. 013). The results were 140. 4± 15. 2, 120. 2± 10. 4 and 111. 6± 11. 2 μ Sv in Cranex Tome (p=0. 208), which reveals no significant difference between two systems. Conclusion: There are no significant differences between the mean absorbed dose of surveyed models in panoramic imaging by two units (PM 2002 CC Proline and Cranex Tome). These results were less than occupational exposure recommended by ICRP, even at the highest calculated doses.

Background & Objectives: Systematic monitoring of exposure levels for radiation workers and other employees who might recive radiation is the main objective of dosimetry. Biodosimetry is the choice method to assess radiation dose of those exposed unplanned. Biodosimetry may be performed by three techniques: clinical methods, biological methods by genetic and cytogenetic analysis (including dicenteric assay, micronuclei assay, translocation analysis (FISH) and PCC analysis) and biodosimetry based on physical factors (including EPR and OSL). The ideal biodosimetry method is the technique which that offers accurate estimation of accidental or unplanned doses immediately following to exposure, in emergency cases. Other characteristics of an ideal biodosimetry method are high sensitivity, coverage to a wide range of doses, ability to distinguish between acute and chronic exposure. The aim of this study was to comparison of various biodosimetry methods used currently.Material & Methods: In this study, relevant articles on biological dosimetry have been reviewed. Then, specific keywords were selected based on the aim of study and the most recent publication in this field, were collected.Results: Gene expression methods have high sensitivity and low specificity. Dicentric chromosomes in human lymphocytes is still as ideal method of biodosimetry methods. However FISH and EPR techniques Because of the time stability of response, has recently been used widely.Conclusion: Evaluation of various biodosimetry techniques is evident biodosimetry is a practical method, but no single technique may be appropriate to apply for all applications. However, combined methods (especially physical and biological methods) can be helpful.

Having a portable and accessible radiation monitoring tool for members of the society, especially when faced with radiation caused by unwanted nuclear accidents, can provide a solution for radiation exposure monitoring. The monitoring is based on the sensitivity of CCD and CMOS semiconductor of smart mobiles to ionizing radiations. After receiving ionizing radiation such as gamma and X-rays, these sensors can receive the incident beam energy as a result of processes such as the photoelectric phenomenon and create charge carriers by creating ionization in the semiconductor medium of the sensor. The current resulting from the collection of charge carriers will result in the recording of bright (irradiated) and dark (unirradiated) spots on the camera sensor. Measuring the density of bright and dark points in the recorded images provides the possibility of estimating the amount of radiation exposure. In this research, four quality cameras and different brands were selected and dosimetry process for two sources of gamma radiation 60Co and 137Cs have been investigated.  The ratio of the total area of bright spots to the number of illuminated pixels per unit of time, which is proportional to the received dose, was measured and the calibration coefficient was determined for each camera. In the measurements made, the effect of time of death, resolution, stability and reproducibility have been checked and the necessary corrections have been applied. The obtained results show that for all the cameras used, there is a linear relationship between the recorded results and the received dose.

Background: Over recent decades, modern protocols of external beam radiotherapy and radiation techniques such as intensity-modulated radiotherapy (IMRT) have been developed. These methods are extremely sensitive to errors in treatment delivery, so that it is essential to apply a high resolution 3D dosimetry system that has high sensitivity and is capable of measuring and verifying the complex delivery. The ferrous-agarose-xylenol orange (FAX) gels the material properties of which are changed when irradiated have been suggested for such use. Objective: In this study a FAX gel dosimeter was examined for dose linearity for photon and electron beams. Methods: FAX gel was prepared using 0.4 mM (FAS), Fe (NH4)2(SO4)2.6H2O of analytical grade, 25 mM H2SO4 98%, 0.2 mM (XO) xylenol orange-sodium salt, 1% by weight of agarose gel powder and the remaining mass of the solution being highly pure deionized water. FAX gels were exposed to doses up to 20 Gy using 9 MV photon and 6 MeV electron beams by Neptun LINAC. Some general characteristics of FAX such as optical absorbance-dose relationship, sensitivity and reproducibility were analyzed. Results: Although the measurements showed linearity in optical absorbance-dose relationship up to 18 Gy for photons and electrons, oxidation processes continued post-irradiation and storage conditions such as temperature and light affected the response of this dosimeter. The best composition by high sensitivity and stability of dosimeter was found to be 0.4 mM FAS, 0.2 mM XO and 25 mM H2SO4. Conclusion: The above-mentioned FAX gel and UV-visible spectrophotometry as a reader are a sensitive and cheap dosimetry system for radiotherapy.