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The suicide rate among the Iranian population has increased over the past few decades. Descriptive information about this public health challenge could inform health policymakers to prioritize prevention strategies. We described the last updated data from the Iranian forensic medicine between 2016 and 2018. We obtained the data on the fatal suicide cases from the national suicide registry of the Iranian Forensic Medicine Organization (FMO), validated by death certificates and harmonized for epidemiologic studies. This study included 9,021 nationally registered suicide deaths from March 21, 2016, to March 20, 2018. A descriptive statistical approach was used to present the findings. Of 9,021 registered suicide deaths with age range between 10 to 94 years [median=31], 44.6% [n=4,015] was in the category of = 29, 48.0% [n=4,328] between 30 to 59, and 7.4% (n=666) in the category of = 60 years old. The percentage of fatal suicide was obviously higher in men (71.2%, n=6,424). Hanging was the most common method of suicide, both among men (57.7%, n=3706) and women (37.6%, n=976). The frequency of fatal suicide was significantly higher in married than single cases (52.6% vs. 42.9%). Overall, at the national level, the most common suicide method was hanging (51.9%), followed by self-poisoning (25.8%) and self-immolation (6.8%). We found evidence of age- and gender differences in suicide mortality across the country. Men, people in younger age groups, and married couples could be considered as the target population for preventive interventions in Iran. [ABSTRACT FROM AUTHOR]

Introduction: This study aims to investigate the influence of background activity variation on image quantification in differently reconstructed PET/CT images. Methods: Measurements were performed on a Discovery-690 PET/CT scanner using a custom-built NEMA-like phantom. A background activity level of 5.3 and 2.6 kBq/ml 18F-FDG were applied. Images were reconstructed employing four different reconstruction algorithms: HD (OSEM with no PSF or TOF), PSF only, TOF only, and TOFPSF, with Gaussian filters of 3 and 6.4 mm in FWHM. SUVmax and SUVpeak were obtained and used as cut-off thresholding; Metabolic Tumor Volume (MTV) and Total Lesion Glycolysis (TLG) were measured. The volume recovery coefficients (VRCs), the relative percent error (ΔMTV), and Dice similarity coefficient were assessed with respect to true values. Results: SUVmax and SUVpeak decreased and MTV increased as function of increasing the background dose. The most differences occur in smaller volumes with 3-mm filter; Non-TOF and Non-PSF reconstruction methods were more sensitive to increasing the background activity in the smaller and larger volumes, respectively. The TLG values were affected in the small lesions (decrease up to 12%). In a range of target volumes, differences between the mean ΔMTV in the high and low background dose varied from -11.8% to 7.2% using SUVmax and from 2.1% to 7.6% using SUVpeak inter reconstruction methods. Conclusion: The effect of the background activity variation on SUV-based quantification in small lesion was more noticeable than large lesion. The HD and TOFPSF algorithms had the lowest and the highest sensitivity to background activity, respectively. [ABSTRACT FROM AUTHOR]

Background: The accurate dose delivery in intraoperative radiotherapy (IORT) tightly depends on the precision of measured dose by the ion chamber. Output factor (OF) measurement of dedicated intraoperative electron radiotherapy (IOERT) accelerators using ion chamber faces some technical challenges including determination of Ksat. Objectives: The goal was to evaluate the performance of ethanol chlorobenzene (ECB) dosimeter in measuring the OF of intraoperative electron beam and to compare the results to those of ionometric dosimetry and Monte Carlo simulation. Consequemtly we determined the Ksat of employed ion chamber through comparison of the ECB response to ion chamber. Materials and Methods: LIAC dedicated accelerator (LIAC Sordina SpA, Italy) was used for irradiation. To calculate the Ksat, ECB and Advanced Markus chamber were placed at the depth of maximum dose for different energies of LIAC accelerator. Then, Ksat was calculated through comparison of the obtained results. To measure the OF of electron beam, ECB was placed at the depth of maximum dose for each combination of energy/applicator size, and the absorbed dose was determined. Obtained results were compared to those of Advanced Markus chamber and Monte Carlo simulation. Results: The results of Ksat measurement showed that there is a very good agreement between the practically obtained Ksat and theoretical values determined by Laitano formalism at different energies (the maximum difference between the results was lower than 1%). The results of ECB OF measurement were in accordance to the results of ionometric dosimetry and Monte Carlo simulation (the maximum difference between the results was about 1.5% and 1.7%, respectively). Conclusion: Based on the results, it may be concluded that the ECB dosimeter could be considered as an accurate tool for both OF measurement of intraoperative electron beam and cross calibration of employed ion chambers for absolute dosimetry (determination of the Ksat). [ABSTRACT FROM AUTHOR]