3 research outputs found
How much should you worry about contaminant neutrons in spatially fractionated grid radiation therapy?
No full textNeutron contamination in radiation therapy is of concern in treatment with high-energy photons (> 10 MV). With the development of new radiotherapy modalities such as spatially fractionated grid radiation therapy (SFGRT) or briefly grid radiotherapy, more studies are required to evaluate the risks associated with neutron contamination. In 15 MV SFGRT, high- Z materials such as lead and cerrobend are used as the block on the tray of linear accelerator (linac) which can probably increase the photoneutron production. On the other hand, the high-dose fractions (10-20 Gy) used in SFGRT can induce high neutron contamination. The current study was devoted to addressing these concerns via compression of neutron fluence (Φn) and ambient dose equivalent (H*n 10 ) at the patient table and inside the maze between SFGRT and conventional fractionated radiation therapy (CFRT). The main components of the 15 MV Siemens Primus equipped with different grids and located inside a typical radiotherapy bunker were simulated by the MCNPX® Monte Carlo code. Evidence showed that the material used for grid construction does not significantly increase neutron contamination inside the maze. However, at the end of the maze, neutron contamination in SFGRT is significantly higher than in CFRT. In this regard, a delay time of 15 minutes after SFGRT is recommended for all radiotherapy staff before entering the maze. It can be also concluded that H*n 10 at the patient table is at least 10 times more pronounced than inside the maze. Therefore, the patient is more at risk of neutrons compared to the staff. The H*n 10 at the isocenter in SFGRT with grids made of lead and cerrobend was nearly equal to CFRT. Nevertheless, it was dramatically lower than in CFRT by 30% if the brass grid is used. Accordingly, SFGRT with the brass grid is recommended, from radiation protection aspects. © 2023 Mahmoudi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Social Capital of Parents of Children and Adolescents and Its Relation to Psychiatric Disorders; A Population-Based Study
No full textSocial capital is a complex concept that is considered an effective factor in the development of societies. Considering the importance of burdens of psychiatric disorders in Iran, we studied the relationship between various dimensions of social capital of parents of children and adolescents and psychiatric disorders among them. In this cross-sectional study, 18,940 parents of children and adolescents aged 6 to 18 years old were randomly selected from all provinces of Iran and were evaluated by the Millon clinical multiaxial inventory-III (MCMI-III) and a modified version of Nahapiet and Ghoshal questionnaire. MCMI-III was designed as a self-report tool for investigating psychiatric clinical disorders and personality traits in the general population. Modified Nahapiet and ghoshal questionnaire has 20 items and measures four components of social capital included trust, values, communication, and collaboration. Validity and reliability of both questionnaires have been approved in Iran. In the regression model, the relationship between social capital components and clinical and sever clinical syndromes, in the form of regression weight and standard weight for trust was � 0.558 and � 0.062 with p value less than 0.0001, and for values was � 0.466 and � 0.057, respectively, with p value less than 0.0001. There was a reverse correlation between social capital components of parents of children and adolescents and psychiatric disorders in Iran. In regression statistical models, the two components of values and trust were negative predictors of psychiatric disorders. Considering the high prevalence of psychiatric disorders in Iran, it seems that the strengthening of cognitive and structural aspects of social capital of parents of children and adolescents is one of the effective factors in reducing the prevalence of these disorders among them. © 2021, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature
Acceptability of HIV Rapid Testing in Diverse Clinical Settings in Iran
Get PDFIntroduction: Rapid HIV testing in clinical settings can identify previously undiagnosed persons and link them to care, as well provide patients with knowledge of their serostatus and risk reduction counseling. We conducted a survey to characterize factors affecting the acceptance or declining of rapid HIV testing among Iranian patients.Methods: This cross-sectional survey was conducted from October 2014 to December 2014 with patients in three different health care centers (an emergency department in an urban hospital, a rural health centre, a voluntary counseling and testing centre (VCT) within Imam Khomeini Hospital, Tehran, Iran and a rural health centre). Participants completed a semi-structured face-to-face questionnaire and were tested by an HIV rapid test (Chembio Sure Check).Results: Of 222 participants, 25 participants were from the urban emergency department, 40 from the urban VCT program, and 157 from the rural health care centre. All did the rapid HIV test; all were HIV negative. HIV-related risk profiles found the urban emergency department patients more likely to have multiple partners (26%, P<0.01) and history of sexually transmitted diseases (27%, P<0.001) compared to VCT patients (9% and 3%, respectively) and rural clinic patients (4% and 1%, respectively). Emergency department patients were also more willing to pay for a HIV rapid test (44%, P<0.01), doing a rapid self-test at home (84%,P=0.01), preferring pharmacies as a place for providing rapid tests (80%, P=0.001). Also level of participants’ awareness was considerably different between mentioned centres (median=11, 12, 10 for emergency department, VCT and rural Health care centre respectively; P=0.012).Conclusions: Increasing knowledge about HIV rapid testing, its availability, and keeping costs low can expand the desire to use the test and ultimately prevent the spread of HIV through lack of knowing one’s serostatus and lack of treatment. Emergency departments in urban Iran may be an opportunity to test persons at high risk for HIV infection
