Critical discussion of different dose–volume parameters for rectum and urethra in prostate brachytherapy

PurposeTo compare different dose–volume histogram (DVH) parameter concepts used for rectum and urethra.Methods and MaterialsThirty-eight postplan CT scans were used to contour the rectum with only one outer contour and as a wall structure. DVH analysis included dose to absolute and relative volumes of both contour types, from RD_0.1cc to RD_10cc and from RDmax to RD30, respectively. Volume parameters are reported (RV50–RV300) in cubic centimeters and percentages. The analysis of urethral dose parameters was based on 55 CTs with a urethral catheter. Relative (UD100 to UDmax) and absolute volume parameters (UD_0.5cc to UD_0.1cc, UV100, UV150) were evaluated, and also correlated to prostate parameters. The analysis was repeated for 10 MRI-based interstitial high-dose rate cases.ResultsThe correlation between organ and wall results was high for RD1, RD_2cc, and RD_0.1cc, with differences of <5%. DVH parameters reporting dose to a relative volume (e.g., RD10) or a relative volume related to a certain dose (e.g., RV100 [%]) are sensitive to the number of contoured slices. Dmax has a high uncertainty due to the sampling algorithm. RV100 (145 Gy) of 1.5 cc is similar to an RD_2cc of 130 Gy.The urethral UD10 and UD_0.1cc correlate with a mean difference of 1%. The ratios of UD5/UD30, UD10/UD30, and UD5/UD10 were 1.12, 1.09, and 1.03, respectively. The correlation between D90 and D10 for prostate to urethra UD10 was poor.ConclusionsOnly absolute volume parameters are stable in relation to different contouring concepts. When delineating the outer rectum contour, only RD_2cc and RD_0.1cc can be used. RV₁₀₀ in cc correlates to RD_2cc. Reporting UD5, UD10, and UD30 together is redundant. Additional information is given when reporting UV100 or UV150.     

Human cartilage fragments in a composite scaffold for single-stage cartilage repair: an in vitro study of the chondrocyte migration and the influence of TGF-β1 and G-CSF

Purpose

Minced chondral fragments are becoming popular as a source of cells for cartilage repair, as a growing interest is developing towards one-stage procedures to treat cartilage lesions. The purpose of this study is to (A) compare cell outgrowth from cartilage fragments of adult and young donors using two different types of scaffolds and (B) evaluate the influence of transforming-growth-factor-β1 (TGF-β1) and granulocyte colony-stimulating factor (G-CSF) on chondrocyte behaviour.

Methods

In part (A) cartilage fragments from adult and young donors were either loaded onto an HA-derivative injectable paste scaffold or onto an HA-derivative membrane scaffold. Construct sections were then examined for cell counting after 1, 2 and 3 months. In part (B) only membrane scaffolds were prepared using cartilage fragments from young donors. Constructs were cultured either in standard growth medium or in the presence of specific growth factors, such as TGF-β1 or G-CSF or TGF-β1 + G-CSF. After 1 month, construct sections were examined for cell counting. Expression of chondrocyte markers (SOX9, CD151, CD49c) and proliferative markers (β-catenin, PCNA) was assessed using immunofluorescence techniques, both in unstimulated construct sections and in cells from unstimulated and stimulated construct cultures.

Results

Part (A): histological analysis showed age-dependent and time-dependent chondrocyte migration. A significant difference (p < 0.05) was observed between young and older donors at the same time point. No difference was detected between the two types of scaffolds within the same group at the same time point. Part (B): after 1 month, the number of migrating cells/area significantly increased due to exposure to TGF-β1 and/or G-CSF (p < 0.05). Immunofluorescence revealed that outgrowing cells from unstimulated scaffold sections were positive for SOX9, CD151, CD49c and G-CSF receptor. Immunofluorescence of cells from construct cultures showed an increase in β-catenin in all stimulated groups and an increased PCNA expression in G-CSF-exposed cultures (p < 0.05).

Conclusion

Outgrowing cells may represent a subset of chondrocytes undergoing a phenotypic shift towards a proliferative state. TGF-β1, and to a greater extent G-CSF, may accelerate this outgrowth. The clinical relevance of this study may involve a potential future clinical application of scaffolds preloaded with growth factors as an additional coating for chondral fragments. Indeed, a controlled delivery of G-CSF, widely employed in various clinical settings, might improve the repair process driven by minced human cartilage fragments during one-stage cartilage repair.     

Discussion of the features of suicide trends in 1994–1995 and 2019–2020: The need for different contents in suicide prevention measures for both periods in Japan from the viewpoint of the present

Japan is a country that is prone to natural disasters. This study compared the characteristics of suicide trends before and after the Great Hanshin-Awaji Earthquake, and during the current COVID-19 pandemic 25 years later.In the present study, we examined the annual number of suicides, the number of suicides by age group, and the reason for suicide during the period associated with the earthquake (1994–1995) and the period associated with the pandemic (2019–2020). This study used statistical analyses to compare the two periods. Our findings suggest that research needs to be conducted from the perspective of legal medicine and social medicine to devise current and future measures to prevent suicides.During the first period, suicides increased in 1995 compared to 1994. Suicide due to economic and life problems increased significantly. During the second period, suicides increased in 2020 compared to 2019. Suicides by males decreased significantly and those by females increased significantly; suicides by individuals aged 19 or under and by those aged 20–29 increased significantly, while suicides by individuals aged 60–69 decreased significantly; and suicides due to “other problems” increased significantly, while suicides due to economic and life problems decreased significantly.Ongoing studies of detailed trends in suicides due to the effects of COVID-19 need to be conducted in the future, and it is important to determine suicide risk due to the effects of COVID-19. Legal medicine and social medicine are fields that conduct such studies and that can offer science-based responses to these trends.     

Simultaneous PET–MR acquisition and MR-derived motion fields for correction of non-rigid motion in PET

Objective  

Positron emission tomography (PET) provides an accurate measurement of radiotracer concentration in vivo, but performance can be limited by subject motion which degrades spatial resolution and quantitative accuracy. This effect may become a limiting factor for PET studies in the body as PET scanner technology improves. In this work, we propose a new approach to address this problem by employing motion information from images measured simultaneously using a magnetic resonance (MR) scanner.     

Supply and demand for radiographers in Lithuania: A prognosis for 2012–2030

Background

This is the first ever study on the planning of the supply and demand for radiographers in Lithuania. The aim of this study was to analyze the supply and demand for radiographers in the labor market with respect to their number, structure, and services, and to provide a prognosis for the period of 2012–2030.

Materials and methods

Supply was calculated using two scenarios with differing duration of studies, annual student drop-out rates, rates of failure to start working, the annual number of new entrants into the labor market, and emigration rates. Annual mortality rates, the number of first-year students, and retirement rates were evaluated equally in both scenarios.Two projections of the demand for radiographers, based on the population's differing (by age and gender), need for outpatient radiology services, computed tomography, and magnetic resonance scans. Subsequently, the supply and demand scenarios were compared.

Results

Evaluation of the perspective supply and demand scenarios – which are the most probable – revealed a gap forming during the analyzed period, the predicted specialist shortage will reach 0.13 full-time equivalents per 10,000 population, and in 2030—0.37 full-time equivalents per 10,000 population.

Conclusions

Considering the changes in education of radiographers, the socio-demographic characteristics of the staff, and the increasing need for radiographers’ services, the supply of radiographers during the next two decades will be insufficient. To meet the forecasted demand for radiographers in the perspective scenario, the number of students choosing this specialty from 2013 on should increase by up to 30%.     

A validated method for quantitation of psilocin in plasma by LC–MS/MS and study of stability

A liquid chromatography-electrospray ionization/tandem mass spectrometry method for the quantitation of psilocin in plasma is presented. Sample workup was performed with mixed-mode solid-phase extraction using ascorbic acid and nitrogen for drying to protect the unstable analyte. Calibration curves were linear from 2 to 100?ng/mL, and no selectivity problems occurred. The limit of detection was 0.1?ng/mL, and the limit of quantitation was 0.34?ng/mL. Recovery was >86% and matrix effects were <110%. Both were reproducible. Interday and intraday precisions at different concentrations were 1.5-4.3% relative standard deviation, bias within ±9%. Processed samples were stable in the autosampler for at least 26?h. Furthermore, the stability of psilocin in blood stored at different temperatures over various periods of time was investigated. Samples stored at room temperature showed a continuous decrease of analyte leading to a loss of about 90% after 1?week. Storage in the fridge improved sample stability significantly. Freezing of blood samples led to a not reproducible loss of psilocin.     

Comparative analysis of the applicability of the skeletal age determination methods of Greulich–Pyle and Thiemann–Nitz for forensic age estimation in living subjects

Evaluation of hand ossification is a main pillar of radiological age diagnosis in living subjects. In the present study, we comparatively assessed the Greulich–Pyle and Thiemann–Nitz methods for accuracy of age estimation and degree of acceleration in the respective reference populations. For this, the skeletal age of 649 hand X-rays from German subjects aged 1–18 years was determined by both methods. Accuracy of the age estimates was determined based on regression and measures of certainty. In terms of accuracy, both methods seem to be equally well suited for forensic age diagnostics. The degree of acceleration in the reference populations for the two methods was calculated as the mean difference between the estimated skeletal age and the actual age of a test subject. Compared to the Greulich–Pyle population, the Thiemann–Nitz population was accelerated by 0.44 years in both male and female subjects. When an expert opinion is required and one cannot exclude the possibility that the investigated subject may come from a population with a high acceleration status, the Thiemann–Nitz method should preferably be used to prevent overestimation of age.     

Management of Acute Contrast Reactions—Understanding Radiologists' Preparedness and the Efficacy of Simulation-Based Training in Canada

Purpose

Acute radiologic emergencies, primarily severe contrast reactions, are rare but life-threatening events. Given a generalized paucity of formalized or mandated training, studies have shown that radiologists and trainees perform poorly when acutely managing such events. Moreover, skill base, knowledge, and comfort levels precipitously decline over time given the infrequent occurrence of these events during one's daily practice.The primary aim of this study was to assess radiologists' preparedness for managing acute radiologic emergencies and to determine the efficacy of a high-fidelity simulation based training model in an effort to provide a rationale for similar programs to be implemented on a provincial or national level.

Attentional load of walking in children aged 7–12 and in adults

The amount of attentional resources necessary to walk in children, and how they evolve during childhood remains unclear. This study examined children's gait parameters in different dual-task conditions. 53 children, divided into two age groups (7–9 and 10–12 years old), and 18 adults walked on a mat in three different cognitive conditions: watching a video (video condition), listening its soundtrack (audio condition), and without any additional task (control condition). Questions were asked at the end of the video and audio conditions to make sure that participants were paying attention to the stimuli. A GAITRite® system was used for recording the gait data. Results showed an increase of velocity and step duration, and a decrease of cadence and percentage of double limb support duration from 7 years of age to adulthood during dual-task walking compared with single-task walking. This improvement seemed to be linear from 7 years to adults' age. The interference of dual-task on gait was larger for the video than for the auditory task and decreased with age. We concluded that walking requires a significant amount of attentional resources in children and that children rely more than adults on visual processes for walking.     

Mixed-mode C–C18 monolithic spin-column extraction and GC–MS for simultaneous assay of organophosphorus compounds, glyphosate, and glufosinate in human serum and urine

A rapid and specific method for simultaneous quantitation of organophosphates [fenitrothion (MEP), malathion (MAL), and phenthoate (PAP)], glyphosate (GLYP), and glufosinate (GLUF) in human serum and urine by gas chromatography–mass spectrometry (GC–MS) was validated. All targeted compounds, together with the internal standards [fenitrothion-d ₆ (MEP-d ₆) and dl-2-amino-3-phosphonopropionic acid (APPA)], were extracted from the serum and urine with a mixed-mode C–C₁₈ monolithic spin column. Extracted samples were derivatized with N-methyl-N-(tert-butyldimethylsilyl) trifluoroacetamide (MTBSTFA) containing 1% tert-butyldimethylchlorosilane (TBDMCS). Linear calibration curves for serum and urine spanned the ranges of 0.1–10.0 μg/ml for organophosphates, 10–100.0 μg/ml for GLYP, and 5–100.0 μg/ml for GLUF. Detection limits for serum and urine were 10 and 5 μg/ml for GLYP and GLUF, respectively, and quantitation limits for serum and urine were 10 and 5 μg/ml for GLYP and GLUF, respectively. Both detection and quantitation limits for serum and urine were 0.1 μg/ml for organophosphates. The intra-assay and interassay accuracy and precision (expressed as relative standard deviation, %RSD) evaluated for all compounds were within 96.5–109.5% and 5.9–13.1%, respectively. The recovery of organophosphates from serum and urine, spiked at concentrations of 0.1, 1.5, 5, and 9 μg/ml, ranged from 58.8 to 90.8%. Recovery of GLYP and GLUF from serum and urine, spiked at concentrations of 10 (serum) or 5 (urine), 15, 50, and 90 μg/ml, ranged from 2.6 to 6.9%. This method had a chromatographic run time of 16.0 min. The validated method was successfully applied to a clinical case of GLYP poisoning.     

A new method for high-resolution and high-precision analysis of flunitrazepam and 7-aminoflunitrazepam in human body fluids using a Monolithic SPE SpinTip and UPLC–Q-ToF–MS

Forensic Toxicology - Forensic toxicological analyses of drugs and their metabolites in human specimens usually require extractive pretreatment for successful analysis of substances from the...     

A GC–MS method for the determination of furanylfentanyl and ocfentanil in whole blood with full validation

Purpose

Fentanyl analogues are popular in recent years among drug addicts and have been related to many overdoses and deaths worldwide. Furanylfentanyl, ocfentanil, acetylfentanyl and butyrfentanyl are among the most common of these drugs. Methods for the determination of furanylfentanyl and ocfentanil by gas chromatography–mass spectrometry (GC–MS) in biological samples do not exist, and therefore, their development would be extremely useful for routine toxicological analysis.

Methods

A GC–MS method was developed and fully validated for the determination of furanylfentanyl and ocfentanil in whole blood. This method was also suitable for the determination of acetylfentanyl and butyrfentanyl. The method included solid-phase extraction after protein precipitation using acetonitrile, and it was applied during the toxicological investigation of forensic cases. Methadone-d₃ was used as internal standard for the quantification of the analytes.

Results

The limit of detection and limit of quantification values were 0.30 and 1.0 ng/mL for furanylfentanyl and ocfentanil and 0.15 and 0.50 ng/mL for acetylfentanyl and butyrfentanyl, respectively. The calibration curves were linear (R²?≥?0.993) from 1.00 to 100 ng/mL for furanylfentanyl and ocfentanil and from 0.50 to 50.0 ng/mL for acetylfentanyl and butyrfentanyl. The recoveries were not lower than 85%, while accuracies and precisions were not greater than 6.0% (% error) and 8.0% (% relative standard deviation), respectively, for all four fentanyl analogues.

Conclusions

The developed method is the first one in the literature for the detection of furanylfentanyl and ocfentanil in biological fluids by GC–MS, and it provides very high sensitivity comparable to that by liquid chromatography–tandem mass spectrometry.

     

Brain weight in completed suicide and other cases of death–comparison of recent and previous studies

Background

The weight of human brains is subject of numerous scientific research studies particularly in anatomy, pathology, and forensic medicine. Just a few investigations deal with a possible correlation between psychiatric disorders, especially suicidality, and brain weight. The results are contradictory.

Aims

This study aims to find out if postmortem brain weight is higher in suicide victims considering the discrepancies of previous studies.

Method

In a retrospective study, the weight of brains obtained by autopsies performed in the Institute of Legal Medicine in Frankfurt, Germany, was evaluated. Data of 99 suicide cases (64 males, 35 females) were compared with those obtained from similar number cases of sudden death in a matched pair analysis. In each case, body weight, height, and body mass index were also taken into account.

Results

No significant differences in brain weight were found in suicide victims compared to those of the control group.

Conclusions

The brain weight depends on various parameters such as gender, age, body height, and weight. The selection criteria for suicide cases as well as for the corresponding control population are essential in evaluating the brain weight in suicide.     

Value of diffusion-tensor imaging and fiber tractography in the diagnosis and follow-up of Marchiafava–Bignami disease

Marchiafava–Bignami disease is a rare alcohol-related disorder that results in progressive demyelination and necrosis of the corpus callosum. The diagnosis is based on clinical profiles and neuroimaging features. We report two cases of Marchiafava–Bignami disease studied with MRI, including diffusion-tensor imaging and fiber tractography. We observed decreased fractional anisotropy values in the corpus callosum and clear white matter fiber derangement in the chronic stage. However, extensive corpus callosum involvement in FLAIR sequences, low ADC values and normal FA at presentation are not good predictors of poor outcome.