Radiation cancer risk from doses to newborn infants hospitalized in neonatal intensive care units in children hospitals of Isfahan province

Background: This study aimed to invesgate dose area product (DAP), effecve dose, and radiaon risk in newborn infants hospitalized in neonatal intensive care units in Isfahan and Kashan. Materials and Methods: During a period of six months, DAP for chest X-ray examinaons for newborn infants hospitalized in NICUs of five special hospitals including Behesh (in Kashan), Al-Zahra, Imam Hossein, Amin and Goldis (in Isfahan) were measured using DAP meter. Then, using the dose area product (DAP) and conversion coefficients, the effecve dose was calculated. Radiaon risk per single exposure was esmated by applying 2.8 × 10-2 and 13 × 10-2 factors per Sievert. Also, to esmate the radiaon risk in the exposed populaon, the collecve effecve dose and the menoned factors were used. Results: The mean DAP, the effecve dose, the radiaon risk per single exposure, and the radiaon risk in the exposed populaon were found to be 15.37 ± (1.19), 45.52 ± (3.28), [1.27-5.91] × 10-6, and [0.0045-0.021], respecvely. Conclusion: Findings indicate that the effecve dose and therefore radiaon risk in NICUs for newborn infants is higher than that of other studied cies in Iran. Consequently, it is necessary to aCempt to reduce radiaon dose while maintaining the image quality. In addion, theorecal and praccal training programs are needed to increase the knowledge and skills of radiologic technologists on the concept of As Low As Reasonably Achievable (ALARA) and possible radiaon cancer risks

Knowledge of medical interns and radiology residents, students, and staff about the radiation dose received by patients in different imaging methods

Background and purpose: Knowledge on the risks of radiation during diagnostic imaging is necessary to protect patients against the hazards of ionizing radiation. The aim of this study was to investigate the level of knowledge of interns, radiology residents, radiology students, and staff about radiation doses received by patients in radiological examinations. Materials and methods: During a cross-sectional study, 163 individuals (interns, radiology residents, students, and staff in Kashan University of Medical Sciences) were asked to identify the average dose of radiation received by patients. A researcher-made questionnaire was administered. Average of correct answers in the groups was analyzed using the SPSS 16 software. The scores above 75%, 75-50%, 50-25%, and below 25% were considered as very good, good, moderate, and poor levels of knowledge, respectively. Results: The mean scores for the level of knowledge about the dose received by patients were 57.9±2.45% and 52.4±2.65% in the staff and radiology students, while it was 35.35±-1.65% and 41.35±6% in interns and residents, respectively. Conclusion: In this study most of the radiology staff and students had good levels of knowledge about the radiation dose received by patients during diagnostic radiological methods. Therefore, revising curricula with more emphasis on radiation protection is recommended for medical interns and residents. © 2016, Mazandaran University of Medical Sciences. All rights reserved

Mouse Lung Conditioned Medium Induces Short Term Erythropoiesis in Mouse Long Term Bone Marrow Culture System

Dexter-type long-term bone marrow culture is a myelopoietic culture system that allows maintenance of  mouse and human hematopoiesis in vitro over a period of several months. In mouse unperturbed long-term  bone marrow culture, erythropoiesis activity is limited to the production of immature erythroid progenitors  (BFU-E) from primitive hematopoietic stem cells. In this study the effects of mouse lung conditioned  medium (MLCM) as a source of myeloid growth factors, on long-term mouse bone marrow cultures was  studied. Numbers of cells in adherent and non-adherent layers of cultures were counted weekly and the  morphological appearances of mature cells that were produced in non-adherent layers were analyzed. In the  presence of MLCM, mature nonnucleated and hemoglobinized red blood cells were produced in the nonadherent  layers of the cultures.

Measuring the dose�width product and proposing the local diagnostic reference level in panoramic dental radiography: a multi-center study from Iran

Objective: Although radiation exposure associated with dental radiography is relatively low, patient exposure must be kept practically low. Therefore, it is necessary for each country to establish its own diagnostic reference levels (DRLs) suitable for its equipment and practice. In the present study, dose-width product (DWP) values for panoramic dental radiography were measured and a local DRL was established. Methods: Five panoramic devices from five radiology clinics of Kashan, Iran were selected to measure the DWP values of panoramic dental radiography. To investigate the DWP values, the parameters of each patient�s exposure (e.g., tube voltage, tube current, and exposure time) at these five radiology clinics were extracted. Then, the dose value received by each patient was measured based on a CT pencil chamber. Finally, the overall median DWP values for the patients with small, medium, and large sizes were obtained, and these values were considered as the local DRLs for panoramic dental radiography. Results: A total of 99 adult patients were included in the present study. The findings demonstrated that the median and third-quartile DWP values for these five radiology clinics ranged from 42.3 to 94.3 and 49.7 to 142.8 mGy mm, respectively. The local DRL values, which were established as the overall median DWP values, were 43.4, 52.0, and 80.3 mGy mm for the adults with small, medium, and large sizes, respectively. Conclusion: The local DRL proposed in this study for the adult with standard/medium size was lower than those proposed by other reports and seemed acceptable for panoramic radiography in Kashan, Iran. © 2020, Japanese Society for Oral and Maxillofacial Radiology and Springer Nature Singapore Pte Ltd

Mitigation of radiation-induced lung pneumonitis and fibrosis using metformin and melatonin: A histopathological study

Background and objectives: Pneumonitis and fibrosis are the most common consequences of lung exposure to a high dose of ionizing radiation during an accidental radiological or nuclear event, and may lead to death, after some months to years. So far, some anti-inflammatory and antioxidant agents have been used for mitigation of lung injury. In the present study, we aimed to detect possible mitigatory effects of melatonin and metformin on radiation-induced pneumonitis and lung fibrosis. Materials and methods: 40 male mice were divided into 4 groups (10 mice in each). For control group, mice did not receive radiation or drugs. In group 2, mice were irradiated to chest area with 18 Gy gamma rays. In groups 3 and 4, mice were first irradiated similar to group 2. After 24 h, treatment with melatonin as well as metformin began. Mice were sacrificed after 100 days for determination of mitigation of lung pneumonitis and fibrosis by melatonin or metformin. Results: Results showed that both melatonin and metformin are able to mitigate pneumonitis and fibrosis markers such as infiltration of inflammatory cells, edema, vascular and alveolar thickening, as well as collagen deposition. Conclusion: Melatonin and metformin may have some interesting properties for mitigation of radiation pneumonitis and fibrosis after an accidental radiation event. © 2019 by the authors. Licensee MDPI, Basel, Switzerland

Comparison of dosimetric parameters of small-field electron beams between Advanced Markus, Semiflex 3D, and Diode E responses

The usage of dosimetry of small fields in radiotherapy to measure radiation dose is difficult because of high-dose gradients, lateral electronic disequilibrium, and detector volume effects. In this study, three dosimeters namely, Markus, Semiflex 3D, and Diode E were tested using the Elekta-accelerator electron beams. The electron beam parameters, penumbra, and output factor were determined using these dosimeters for each field size and energy. According to the results, Diode E and Advanced Markus exhibited the greatest difference in Rq among the electron beam parameters. Furthermore, the greatest difference in penumbra was observed between Diode E and Advanced Markus for the field size of 3 cm2 at 10 MeV. In terms of output factor, three dosimeters exhibited the greatest difference between Diode E and Advanced Markus for the field size of 3 cm2 at 10 MeV. The findings indicate that the Semiflex 3D can be regarded as an appropriate dosimeter for electron small-field dosimetry. © 2020, Japanese Society of Radiological Technology and Japan Society of Medical Physics

Melatonin Attenuates Upregulation of Duox1 and Duox2 and Protects against Lung Injury following Chest Irradiation in Rats

Objective: The Lung is one of the most radiosensitive organs of the body. The infiltration of macrophages and lymphocytes into the lung is mediated via the stimulation of T-helper 2 cytokines such as IL-4 and IL-13, which play a key role in the development of fibrosis. It is likely that these cytokines induce chronic oxidative damage and inflammation through the upregulation of Duox1 and Duox2, which can increase the risk of late effects of ionizing radiation (IR) such as fibrosis and carcinogenesis. In the present study, we aimed to evaluate the possible increase of IL-4 and IL-13 levels, as well as their downstream genes such as IL4ra1, IL13ra2, Duox1, and Duox2. Materials and Methods: In this experimental animal study, male rats were divided into 4 groups: i. Control, ii. Melatonin-treated, iii. Radiation, and iv. Melatonin (100 mg/kg) plus radiation. Rats were irradiated with 15 Gy 60Co gamma rays and then sacrificed after 67 days. The expressions of IL4ra1, IL13ra2, Duox1, and Duox2, as well as the levels of IL-4 and IL-13, were evaluated. The histopathological changes such as the infiltration of inflammatory cells, edema, and fibrosis were also examined. Moreover, the protective effect of melatonin on these parameters was also determined. Results: Results showed a 1.5-fold increase in the level of IL-4, a 5-fold increase in the expression of IL4ra1, and a 3-fold increase in the expressions of Duox1 and Duox2. However, results showed no change for IL-13 and no detectable expression of IL13ra2. This was associated with increased infiltration of macrophages, lymphocytes, and mast cells. Melatonin treatment before irradiation completely reversed these changes. Conclusion: This study has shown the upregulation of IL-4-IL4ra1-Duox2 signaling pathway following lung irradiation. It is possible that melatonin protects against IR-induced lung injury via the downregulation of this pathway and attenuation of inflammatory cells infiltration. © 2019 Royan Institute (ACECR). All rights reserved

Determination of effective source to surface distance and cutout factor in small fields in electron beam radiotherapy: A comparison of different dosimeters

Objective: The main purpose of this study is to calculate the effective source to surface distance (SSDeff) of small and large electron fields in 10, 15, and 18 MeV energies, and to investigate the effect of SSD on the cutout factor for electron beams a linear accelerator. The accuracy of different dosimeters is also evaluated. Materials and methods: In the current study, Elekta Precise linear accelerator was used in electron beam energies of 10, 15, and 18 MeV. The measurements were performed in a PTW water phantom (model MP3-M). A Semiflex and Advanced Markus ionization chambers and a Diode E detector were used for dosimetry. SSDeff in 100, 105, 110, 115, and 120 cm SSDs for 1.5 � 1.5 cm2 to 5 � 5 cm2 (small fields) and 6 � 6 cm2 to 20 � 20 cm2 (large fields) field sizes were obtained. The cutout factor was measured for the small fields. Results: SSDeff in small fields is highly dependent on energy and field size and increases with increasing electron beam energy and field size. For large electron fields, with some exceptions for the 20 � 20 cm2 field, this quantity also increases with energy. The SSDeff was increased with increasing beam energy and field size for all three detectors. Conclusion: The SSDeff varies significantly for different field sizes or cutouts. It is recommended that SSDeff be determined for each electron beam size or cutout. Selecting an appropriate dosimetry system can have an effect in determining cutout factor. © 2020 Mohamad Reza Bayatiani et al., published by Sciendo 2020

Measuring the dose–width product and proposing the local diagnostic reference level in panoramic dental radiography: a multi-center study from Iran

Objective: Although radiation exposure associated with dental radiography is relatively low, patient exposure must be kept practically low. Therefore, it is necessary for each country to establish its own diagnostic reference levels (DRLs) suitable for its equipment and practice. In the present study, dose-width product (DWP) values for panoramic dental radiography were measured and a local DRL was established. Methods: Five panoramic devices from five radiology clinics of Kashan, Iran were selected to measure the DWP values of panoramic dental radiography. To investigate the DWP values, the parameters of each patient’s exposure (e.g., tube voltage, tube current, and exposure time) at these five radiology clinics were extracted. Then, the dose value received by each patient was measured based on a CT pencil chamber. Finally, the overall median DWP values for the patients with small, medium, and large sizes were obtained, and these values were considered as the local DRLs for panoramic dental radiography. Results: A total of 99 adult patients were included in the present study. The findings demonstrated that the median and third-quartile DWP values for these five radiology clinics ranged from 42.3 to 94.3 and 49.7 to 142.8 mGy mm, respectively. The local DRL values, which were established as the overall median DWP values, were 43.4, 52.0, and 80.3 mGy mm for the adults with small, medium, and large sizes, respectively. Conclusion: The local DRL proposed in this study for the adult with standard/medium size was lower than those proposed by other reports and seemed acceptable for panoramic radiography in Kashan, Iran. © 2020, Japanese Society for Oral and Maxillofacial Radiology and Springer Nature Singapore Pte Ltd

Radiation-induced dual oxidase upregulation in rat heart tissues: Protective effect of melatonin

Background: Radiation-induced heart injury can lead to increased risk of heart failure, attack, and ischemia. Some studies proposed IL-4 and IL-13 as two important cytokines that are involved in late effects of ionizing radiation. On the other hand, these cytokines may, through upregulation of Duox1 and Duox2, induce chronic oxidative stress, inflammation, and fibrosis. In this study, we evaluated the upregulation of Duox1 and Duox2 pathways in hearts following chest irradiation in rats and then detected possible attenuation of them by melatonin. Materials and Methods: Twenty male Wistar rats were divided into four groups: (1) control; (2) melatonin treated (100 mg/kg); (3) radiation (15 Gy gamma rays); (4) melatonin treated before irradiation. All rats were sacrificed after 10 weeks and their heart tissues collected for real-time PCR (RT-PCR), ELISA detection of IL-4 and IL-13, as well as histopathological evaluation of macrophages and lymphocytes infiltration. Results: Results showed an upregulation of IL-4, IL4ra1, Duox1, and Duox2. The biggest changes were for IL4ra1 and Duox1. Treatment with melatonin before irradiation could attenuate the upregulation of all genes. Melatonin also caused a reduction in IL-4 as well as reverse infiltration of inflammatory cells. Conclusion: Duox1 and Duox2 may be involved in the late effects of radiation-induced heart injury. Also, via attenuation of these genes, melatonin can offer protection against the toxic effects of radiation on the heart. © 2019 by the authors