Monte Carlo calculated beam quality correction factors for high energy electron beams.

PURPOSE: As the dosimetry protocol TRS 398 is being revised and the ICRU report 90 provides new recommendations for density correction as well as the mean ionization energies of water and graphite, updated beam quality correction factors kQ are calculated for reference dosimetry in electron beams and for independent validation of previously determined values. METHODS: Monte Carlo simulations have been performed using EGSnrc to calculate the absorbed dose to water and the dose to the active volumes of ionization chambers SNC600c, SNC125c and SNC350p (all Sun Nuclear, A Mirion Medical Company, Melbourne, FL). Realistic clinical electron beam spectra were used to cover the entire energy range of therapeutic electron accelerators. The Monte Carlo simulations were validated by measurements on a clinical linear accelerator. With regards to the cylindrical chambers, the simulations were performed according to the setup recommendations of TRS 398 and AAPM TG 51, i.e. with and without consideration of a reference point shift by rcav/2. RESULTS: kQ values as a function of the respective beam quality specifier R50 were fitted by recommended equations for electron beam dosimetry in the range of 5 MeV to 18 MeV. The fitting curves to the calculated values showed a root mean square deviation between 0.0016 and 0.0024. CONCLUSION: Electron beam quality correction factors kQ were calculated by Monte Carlo simulations for the cylindrical ionization chambers SNC600c and SNC125c as well as the plane parallel ionization chamber SNC350p to provide updated data for the TRS 398 and TG 51 dosimetry protocols.

Is there a correlation between migraine and eating disorders? A systematic literature review.

INTRODUCTION: Migraine is a common primary headache disorder, which affects mainly young females, usually those with some specific personality traits including neuroticism and obsessive-compulsive disorder. Among many factors that may trigger headache are to be found those associated with eating patterns and behaviours. Eating disorders are psychiatric disorders of abnormal eating or weight-control behaviours. According to the most up-to-date classification, six main types are identified, including anorexia nervosa, bulimia nervosa, and binge eating disorder. Similar to migraine, eating disorders are mainly diagnosed in young adults and, moreover, personality pattern, in at least some of the eating disorders, is also suggested to be consistent. MATERIAL AND METHODS: This systematic review aimed to summarise the available literature related to this topic. We performed an electronic article search through the Embase, PubMed, and Cochrane databases and included 16 articles into analysis in accordance with PRISMA 2020 guidelines. RESULTS: Most of the studies revealed the presence of a putative correlation between migraine and eating disorders, and these encourage further investigations. Moreover, apart from the clinical aspect, also the pathogenesis underlying both disorders is suggested to be similar. More frequent co-occurrence of other psychiatric disorders in migraineurs, such as depression and anxiety, was reported and should be considered in future research. Furthermore, adverse interactions between pharmacotherapy and symptoms of comorbid conditions underline the importance of this problem. CONCLUSIONS: A correlation between migraine and eating disorders appears highly probable. However, further investigations are required focusing on diverse aspects such as clinical, psychological, and pathogenic.

Health behaviors and problems in Polish homeless men.

Introduction: Homelessness is considered to be a global problem, independent of the material situation of a given country and occurring in most societies around the world. Aim of the study: Assessment of the preferred health behaviors of homeless people. Materials and methods: The study covered 153 men who are homeless and 312 men who are not homeless. The original questionnaire of homeless, and validated the Satisfaction with Life Scale (SWLS), the Health Behavior Inventory (HBI), the General Self-Efficacy Scale (GSES) and the Multidimensional Health Locus of Control (MHLC) Scale were used. The research covered fully completed questionnaires from 153 homeless men staying in Bialystok and Gdansk homelss centers. Results: On average, the homeless men assessed their health at 6.0 ± 2.7 points, and the non-homeless at 7.8 ± 2.2 points (p < 0.001). Significant differences were found between people experiencing a homelessness crisis and the control group in selected aspects concerning the everyday life hygiene of the respondents, health self-assessment, declarations of visits to a specialist and carrying out check-ups, level of satisfaction with life, coping with difficult situations, preferred pro-health behaviors and dimensions of health control. In the used scales, SWLS, HBI, GES, and MHCL, the majority of homeless men obtained average scores. They were rather dissatisfied with their lives, with a low level of effectiveness in coping with difficult situations and obstacles, a low level of health behaviors, and in the scope of health, control increasing the impact of chance. Conclusion: The level of the presented health behaviors showed statistically significant diversification with all dimensions of the health locus of control, and its internal dimension with age, homelessness phase, the respondents' criminal history, being under constant medical care, and self-assessment of health.

Effect of various factors on energy drinks consumption, and their connection with alcohol consumption.

Energy drinks (EDs) have become widely popular among adolescents and young adults. Excessive consumption of EDs can lead to ED abuse and alcohol abuse. Therefore, this study has aimed to analyse the consumption of EDs in a group of patients suffering from alcohol dependence and among young adults, considering such issues as the amounts consumed, underlying reasons and threats arising from excessive consumption of ED and their mixing with alcohol (AmED). The study included 201 men (101 patients treated due to alcohol dependence and 100 young adults/students). Each research participant responded to questions in a survey designed by the researchers (socio-demographic data, clinical data, including consumption of ED, AmED and alcohol), the MAST and SADD. The participants also had their arterial blood pressure measured. EDs were consumed by 92% of the patients and 52% of young adults. A statistically significant dependence was confirmed between consumption of ED and tobacco smoking (p < 0.001), as well as the place of residence (p = 0.044). For 22% of the patients, ED consumption had an effect on alcohol consumption, where 7% admitted to feeling an increased urge to drink alcohol, and 15% said ED consumption decreased it. A statistically significant relationship (p < 0.001) was also shown between ED consumption and the consumption of EDs mixed with alcohol (AmED). This study may implicate that widespread consumption of EDs predisposes to the consumption of alcohol mixed with ED or separate.

Experimental and Monte Carlo-based determination of magnetic field correction factors k B , Q $k_{B,Q}$ in high-energy photon fields for two ionization chambers.

BACKGROUND: The integration of magnetic resonance tomography into clinical linear accelerators provides high-contrast, real-time imaging during treatment and facilitates online-adaptive workflows in radiation therapy treatments. The associated magnetic field also bends the trajectories of charged particles via the Lorentz force, which may alter the dose distribution in a patient or a phantom and affects the dose response of dosimetry detectors. PURPOSE: To perform an experimental and Monte Carlo-based determination of correction factors k B , Q $k_{B,Q}$ , which correct the response of ion chambers in the presence of external magnetic fields in high-energy photon fields. METHODS: The response variation of two different types of ion chambers (Sun Nuclear SNC125c and SNC600c) in strong external magnetic fields was investigated experimentally and by Monte Carlo simulations. The experimental data were acquired at the German National Metrology Institute, PTB, using a clinical linear accelerator with a nominal photon energy of 6 MV and an external electromagnet capable of generating magnetic flux densities of up to 1.5 T in opposite directions. The Monte Carlo simulation geometries corresponded to the experimental setup and additionally to the reference conditions of IAEA TRS-398. For the latter, the Monte Carlo simulations were performed with two different photon spectra: the 6 MV spectrum of the linear accelerator used for the experimental data acquisition and a 7 MV spectrum of a commercial MRI-linear accelerator. In each simulation geometry, three different orientations of the external magnetic field, the beam direction and the chamber orientation were investigated. RESULTS: Good agreement was achieved between Monte Carlo simulations and measurements with the SNC125c and SNC600c ionization chambers, with a mean deviation of 0.3% and 0.6%, respectively. The magnitude of the correction factor k B , Q $k_{B,Q}$ strongly depends on the chamber volume and on the orientation of the chamber axis relative to the external magnetic field and the beam directions. It is greater for the SNC600c chamber with a volume of 0.6 cm3 than for the SNC125c chamber with a volume of 0.1 cm3 . When the magnetic field direction and the chamber axis coincide, and they are perpendicular to the beam direction, the ion chambers exhibit a calculated overresponse of less than 0.7(6)% (SNC600c) and 0.3(4)% (SNC125c) at 1.5 T and less than 0.3(0)% (SNC600c) and 0.1(3)% (SNC125c) for 0.35 T for nominal beam energies of 6 MV and 7 MV. This chamber orientation should be preferred, as k B , Q $k_{B,Q}$ may increase significantly in other chamber orientations. Due to the special geometry of the guard ring, no dead-volume effects have been observed in any orientation studied. The results show an intra-type variation of 0.17% and 0.07% standard uncertainty (k=1) for the SNC125c and SNC600c, respectively. CONCLUSION: Magnetic field correction factors k B , Q $k_{B,Q}$ for two different ion chambers and for typical clinical photon beam qualities were presented and compared with the few data existing in the literature. The correction factors may be applied in clinical reference dosimetry for existing MRI-linear accelerators.

The Lack of Influence of Homozygous Long Allele of the 5-HTTLPR Gene on the Severity of Alcohol Craving During 6 Weeks of Rehab Hospitalisation in Comparison to Not Homozygous and Homozygous Short Alleles - Preliminary Report.

Purpose: The aim of this study was to assess changes in the severity of alcohol craving according to allelic variants of the 5-HTTLPR gene polymorphism during hospitalisation and their association with selected clinical variables in alcohol-dependent patients. Patients and Methods: The study is exploratory. Participants were investigated at the 2nd and 6th week of alcohol-dependence therapy in the addiction treatment unit. Recruitment was conducted among alcohol-dependent patients from several Polish drug treatment centres. The total sample size was 130 persons (12 females and 118 males). Study subjects' mean age was 43.0 years. Patients were investigated twice by using the Penn Alcohol Craving Scale (PACS) and Beck Depression Inventory (BDI), and once by using Short Alcohol Dependence Data Questionnaire (SADD) and taking a swab for genetic testing. The polymorphism of the gene encoding the serotonin transporter 5-HTTLPR (SLC6A4) was determined from isolated DNA and its homozygous variants of short/short or long/long alleles and heterozygous short/long alleles were analysed. Results: At 6th week of the follow-up, there was a decrease in the severity of alcohol craving in half of subjects with the short/short allele (p = 0.033) and in one-fifth of subjects with the long/short allele (p = 0.002) of the 5-HTTLPR gene. In subjects with long/long allele of the 5-HTTLPR gene, there was no change in the severity of alcohol craving between 2nd and 6th weeks of the study (p = 0.242). Conclusion: There was no statistical influence of the homozygous long allele of the 5-HTTLPR gene on severity of alcohol craving during 6 weeks of rehab hospitalisation in comparison to not homozygous and homozygous short alleles. The s-allele was associated with decrease of alcohol craving. It may point on the potential need for differentiated rehabilitation methods depending on the genetic diversity of addicted patients and its role in the severity of alcohol craving.

Confusion of Alcohol Craving With Food Hunger in Alcohol-Dependent Individuals Entering In-Patient Drug Treatment.

AIM: To identify the distinguishing characteristics of alcohol dependent patients who confuse alcohol cravings with pre-meal hunger. METHODS: Data were collected at interview on sociodemographic status, clinical status and anthropometry in 179 patients (163 men and 16 women) undergoing in-patient treatment for alcohol dependence. RESULTS: A comparison of the patient subgroups studied showed that patients who did not confuse, and those who did confuse, alcohol craving with pre-meal hunger differed significantly in terms of alcohol craving scale scores (9 vs. 4 points). Patients confusing alcohol cravings with pre-meal hunger were more likely to recognize that experiencing severe pre-meal hunger can cause relapse (67.9 vs. 22.8%) and that not being able to distinguish between the sensations under study also increases the risk of breaking abstinence (75.0% vs. 50.4%). This was independent of severity of dependence and intensity of recent alcohol consumption. CONCLUSIONS: Alcohol-dependent persons who confuse alcohol craving with pre-meal hunger differ from those who do not confuse these hunger pangs in terms of feeling stronger alcohol craving and more frequent occurrence of symptoms accompanying the feeling of alcohol craving during pre-meal hunger. At the start of treatment for alcohol withdrawal, alcohol-dependent individuals who report confusing alcohol cravings with pre-meal hunger are less confident of maintaining abstinence. This is relevant to treatment. The role of possible confounders (depressive symptoms, cognitive and educational deficiency) could not be elucidated definitively.

Validation of an EGSnrc-based Monte Carlo model for a complex 2D-array for technical QA measurements of a linear accelerator.

PURPOSE: Multi-axis ionization chamber arrays can be used for quality assurance (QA) and measurement of linear accelerator (linac) specific data. In this work, the ability of the IC Profiler (Sun Nuclear Corp., Melbourne, Florida) detector array to measure the photon beam quality specifier %dd(10) x $_\textrm {{\it x}}$ and TPR20, 10 was investigated. To investigate the method for beam energy QA using a two-dimensional detector array, a Monte Carlo-based model of the detector array was developed and validated. METHODS: A Monte Carlo-based model of the IC Profiler detector array with Quad Wedge accessories was developed in detail from drawings provided by the manufacturer using the egs++ class library from the EGSnrc code system. Monte Carlo simulations were used to calculate the absorbed dose in the 251 ionization chambers of the IC profiler in the 6 MV Elekta Precise radiation field. To validate the results from the Monte Caro simulations, measurements were performed on clinical 6 MV linacs. To vary the photon beam quality of the Elekta 6 MV linac, the current of the bending magnet was varied. Furthermore, the area ratio A R $AR$ was calculated from IC Profiler measurements with the Quad Wedge accessories. RESULTS: Measurements as well as Monte Carlo simulations confirmed the linear relationship between the area ratio A R $AR$ and the investigated photon beam quality specifier %dd(10) x $_\textrm {{\it x}}$ and TPR20, 10 for the investigated radiation source. Furthermore, the Monte Carlo-simulated data were within the 95% confidence interval of the linear fit to the measured data. This enabled the Monte Carlo-based IC Profiler model to be used for further investigations. The A R $AR$ values were calculated for various electron beam sizes and the angle of incidence on the target of the linac. CONCLUSIONS: A Monte-Carlo-based model of the detector array was developed, which could successfully reproduce measurements, demonstrating that even very complex geometries can be modeled in EGSnrc. Moreover, the study showed that the validated Monte Carlo model has the potential to investigate variations in beam parameters and their effects on AR ratios and %dd(10) x $_\textrm {{\it x}}$ that may not be investigated experimentally. While these findings may help users gain a deeper understanding of the QA method, the Monte Carlo model enables other complex investigations, such as the simulation of measurements in the presence of magnetic fields, or the simulation of measurements on novel treatment delivery techniques and devices.

Investigation of Monte Carlo simulations of the electron transport in external magnetic fields using Fano cavity test.

PURPOSE: Monte Carlo simulations are crucial for calculating magnetic field correction factors kB for the dosimetry in external magnetic fields. As in Monte Carlo codes the charged particle transport is performed in straight condensed history (CH) steps, the curved trajectories of these particles in the presence of external magnetic fields can only be approximated. In this study, the charged particle transport in presence of a strong magnetic field B→ was investigated using the Fano cavity test. The test was performed in an ionization chamber and a diode detector, showing how the step size restrictions must be adjusted to perform a consistent charged particle transport within all geometrical regions. METHODS: Monte Carlo simulations of the charged particle transport in a magnetic field of 1.5 T were performed using the EGSnrc code system including an additional EMF-macro for the transport of charged particle in electro-magnetic fields. Detailed models of an ionization chamber and a diode detector were placed in a water phantom and irradiated with a so called Fano source, which is a monoenergetic, isotropic electron source, where the number of emitted particles is proportional to the local density. RESULTS: The results of the Fano cavity test strongly depend on the energy of charged particles and the density within the given geometry. By adjusting the maximal length of the charged particle steps, it was possible to calculate the deposited dose in the investigated regions with high accuracy (<0.1%). The Fano cavity test was performed in all regions of the detailed detector models. Using the default value for the step size in the external magnetic field, the maximal deviation between Monte Carlo based and analytical dose value in the sensitive volume of the ion chamber and diode detector was 8% and 0.1%, respectively. CONCLUSIONS: The Fano cavity test is a crucial validation method for the modeled detectors and the transport algorithms when performing Monte Carlo simulations in a strong external magnetic field. Special care should be given, when calculating dose in volumes of low density. This study has shown that the Fano cavity test is a useful method to adapt particle transport parameters for a given simulation geometry.

The fast calibration model for dosimetry with an electronic portal imaging device.

PURPOSE: The aim of this study was to develop an algorithm that corrects the image of an electronic portal imaging device (EPID) of a linear accelerator so that it can be used for dosimetric purposes, such as in vivo dosimetry or quality assurance for photon radiotherapy. For that purpose, the impact of the field size, phantom thickness, and the varying spectral photon distribution within the irradiation field on the EPID image was investigated. METHODS: The EPID measurements were verified using reference measurements with ionization chambers. Therefore, absolute dose measurements with an ionization chamber and relative dose measurements with a detector array were performed. An EPID calibration and correction algorithm was developed to convert the EPID image to a dose distribution. The algorithm was validated by irradiating inhomogeneous phantoms using square fields as well as irregular IMRT fields. RESULTS: It was possible to correct the influence of the field size, phantom thickness on the EPID signal as well as the homogenization of the image profile by several correction factors within 0.6%. A gamma index analysis (3%, 3 mm) of IMRT fields showed a pass rate of above 99%, when comparing to the planning system. CONCLUSION: The developed algorithm enables an online dose measurement with the EPID during the radiation treatment. The algorithm is characterized by a robust, non-iterative, and thus real-time capable procedure with little measuring effort and does not depend on system-specific parameters. The EPID image is corrected by multiplying three independent correction factors. Therefore, it can easily be extent by further correction factors for other influencing variables, so it can be transferred to other linear accelerators and EPID configurations.

Monte Carlo calculated beam quality correction factors for two cylindrical ionization chambers in photon beams.

PURPOSE: Although several studies provide data for reference dosimetry, the SNC600c and SNC125c ionization chambers (Sun Nuclear Corporation, Melbourne, FL) are in clinical use worldwide for which no beam quality correction factors kQ are available. The goal of this study was to calculate beam quality correction factors kQ for these ionization chambers according to dosimetry protocols TG-51, TRS 398 and DIN 6800-2. METHODS: Monte Carlo simulations using EGSnrc have been performed to calculate the absorbed dose to water and the dose to air within the active volume of ionization chamber models. Both spectra and simulations of beam transport through linear accelerator head models were used as radiation sources for the Monte Carlo calculations. RESULTS: kQ values as a function of the respective beam quality specifier Q were fitted against recommended equations for photon beam dosimetry in the range of 4 MV to 25 MV. The fitting curves through the calculated values showed a root mean square deviation between 0.0010 and 0.0017. CONCLUSIONS: The investigated ionization chamber models (SNC600c, SNC125c) are not included in above mentioned dosimetry protocols, but are in clinical use worldwide. This study covered this knowledge gap and compared the calculated results with published kQ values for similar ionization chambers. Agreements with published data were observed in the 95% confidence interval, confirming the use of data for similar ionization chambers, when there are no kQ values available for a given ionization chamber.

Initial Study on COMT and DRD2 Gene Polymorphisms as Well as the Influence of Temperament and Character Trait on the Severity of Alcohol Craving in Alcohol-Dependent Patients.

The main aim of this work was to determine the impact of COMT and DRD2 gene polymorphisms together with temperament and character traits on alcohol craving severity alcohol-dependent persons. The sample comprised of 89 men and 16 women (aged 38±7). For the sake of psychological assessment various analytic methods have been applied like the Short Alcohol Dependence Data Questionnaire (SADD), Penn Alcohol Craving Scale (PACS) or Temperament and Character Inventory (TCI) test. The SNP polymorphism of the analyzed genes was determined by Real Time PCR test. The results showed, that the COMT polymorphismmay have an indirected relationship with the intensity and changes in alcohol craving during abstinence. The DRD2 receptor gene polymorphisms are related with the intensity of alcohol craving. It seems that the character traits like "self-targeting", including "self-acceptance", are more closely related to the severity of alcohol craving and polymorphic changes in the DRD2 receptor than temperamental traits. Although this is a pilot study the obtained results appeared to be promising and clearly indicate the link betweengene polymorphisms alcohol craving and its severity.

The Molecular Basis of Alcohol Use Disorder (AUD). Genetics, Epigenetics, and Nutrition in AUD: An Amazing Triangle.

Alcohol use disorder (AUD) is a very common and complex disease, as alcohol is the most widely used addictive drug in the world. This disorder has an enormous impact on public health and social and private life, and it generates a huge number of social costs. Alcohol use stimulates hypothalamic-pituitary-adrenal (HPA) axis responses and is the cause of many physical and social problems (especially liver disease and cancer), accidental injury, and risky sexual behavior. For years, researchers have been trying to identify the genetic basis of alcohol use disorder, the molecular mechanisms responsible for its development, and an effective form of therapy. Genetic and environmental factors are known to contribute to the development of AUD, and the expression of genes is a complicated process that depends on epigenetic modulations. Dietary nutrients, such as vitamins, may serve as one these modulators, as they have a direct impact on epigenomes. In this review, we connect gathered knowledge from three emerging fields-genetics, epigenetics, and nutrition-to form an amazing triangle relating to alcohol use disorder.

Monte Carlo calculation of quality correction factors based on air kerma and absorbed dose to water in medium energy x-ray beams.

Clinical dosimetry is typically performed using ion chambers calibrated in terms of absorbed dose to water. As primary measurement standards for this quantity for low and medium energy x-rays are available only since a few years, most dosimetry protocols for this photon energy range are still based on air kerma calibration. For that reason, data for beam quality correction factors [Formula: see text], necessary for the application of dose to water based protocols, are scarce in literature. Currently the international IAEA TRS-398 Code of Practice is under revision and new [Formula: see text] factors for a large number of ion chambers will be introduced in the update of this protocol. Several international groups provided the IAEA with experimental and Monte Carlo based data for this revision. Within the European Community the EURAMET 16NRM03 RTNORM project was initiated for that purpose. In the present study, Monte Carlo based results for the beam quality correction factors in medium energy x-ray beams for six ion chambers applying different Monte Carlo codes are presented. Additionally, the perturbation factor p Q , necessary for the calculation of dose to water from an air kerma calibration coefficient, was determined. The beam quality correction factor [Formula: see text] for the chambers varied in the investigated energy range by about 4%-5%, and for five out of six chambers the data could be fitted by a simple logarithmic function, if the half-value-layer was used as the beam quality specifier. Corresponding data using different Monte Carlo codes for the same ion chamber agreed within 0.5%. For the perturbation factor p Q , the data did not obey a comparable simple relationship with the beam quality specifier. The variation of p Q for all ion chambers was in the range of 3%-4%. Compared to recently published data, our p Q data is around 1% larger, although the same Monte Carlo code has been used. Compared to the latest experimental data, there are even deviations in the range of 2%.

Impact of new ICRU Report 90 recommendations on calculated correction factors for reference dosimetry.

In 2016 the ICRU published a new report dealing with key data for ionizing radiation dosimetry (ICRU Report 90). New recommendations have been made for the mean excitation energies I for air, graphite and liquid water as well as for the graphite density to use when evaluating the density effect. In addition, the ICRU Report 90 discusses renormalized photoelectric cross sections, but refuses to give a recommendation on the use of renormalization factors. However, the Consultative Committee for Ionizing Radiation recommends to use renormalized photoeffect cross sections. Goal of the present work is to evaluate the impact of these new recommendations on clinical reference dosimetry for high energy photon and electron beams. The beam quality correction factor k Q was calculated by Monte Carlo simulations for compact and parallel plate ionization chambers. In case of photons seven phase space files from clinical accelerators and twelve spectra taken from literature from 4 MV to 24 MV and additionally a 60Co source were applied. As electron source thirteen electron spectra available in literature were used in the range of 4 MeV-21 MeV. The new ICRU recommendations have a small impact on Monte Carlo calculated k Q values for the chosen ionization chambers in the range of 0.1%-0.35% only-the difference increases for higher photon energies. The impact of the ICRU Report 90 recommendations on Monte Carlo calculated stopping power ratios s w,a , perturbation factors p and beam quality correction factors k Q was investigated and confirmed a decrese of s w,a by a fraction of a percent for photon and electron beams. This study indicates that the impact of the new ICRU recommendation is within 0.35%. The determined deviations should be taken into account, when widely published Monte Carlo calculated values are examined.

Validation of the Polish version of the Penn Alcohol Craving Scale (PACS). / Walidacja polskiej wersji Skali Glodu Alkoholu Penn (Penn Alcohol Craving Scale ­ PACS).

OBJECTIVES: The conducted studies were aimed at making a Polish adaptation of the Penn Alcohol Craving Scale (PACS) by B. Flannery and co-workers. The Scale is a self-assessment method, it comprises 5 statements, and is designed to assess alcohol craving experienced by a patient in a week prior to the examination. METHODS: 550 patients with diagnosed alcohol dependence syndrome were examined, and the final analysis included results of 510 persons. The examined group consisted of 396 men and 114 women. The study was made in the 3rd week of their alcohol treatment. There were used: the PENN Craving Scale, the Alcohol Dependence Development Scale (SRUA) (the part in which craving is dealt with), a clinical interview with specially prepared questions about alcohol craving experienced last month and last week, and the Yale-Brown Obsessive Compulsive Intense Drinking Scale. RESULTS: The Polish version of the Penn Scale is characterised by very good psychometric properties - it is a reliable and valid tool. The exploratory and confirmatory factor analyses have proved the existence of one factor. The internal consistency, assessed on the basis of Cronbach's alpha, equalled 0.89. The method displays statistically significant (majority p < 0.0010) relationships with levels of craving experienced last year, last month, and last week before the examination, and also with total score on the Yale-Brown Scale. CONCLUSIONS: The effects of the conducted adaptation works on the Penn Scale speak for recommending the method for scientific research and use in therapeutic practice.

Suicidal thoughts in persons treated for alcohol dependence: The role of selected demographic and clinical factors.

Greater knowledge is needed of potential predictive factors for suicide in cases of alcohol addiction. Therefore, the aim of the study was to identify the socio-demographic variables and clinical factors associated with alcohol dependence which may have an influence on the occurrence of suicidal thoughts in alcohol-dependent patients. A group of 510 patients (396 male and 114 female) diagnosed with alcohol dependence syndrome were interviewed during the third week of therapy according to the Beck Depression Inventory (BDI), the Penn Alcohol Craving Scale (PACS) and the Short Alcohol Dependence Data Questionnaire (SADD). Socio-demographic data was also collected. The results of a binary logistic regression with suicidal thoughts as a dependent variable show that 63 out of the 510 participants (12% of the sample) reported the presence of suicidal thoughts. Alcohol dependence and alcohol craving appear to increase the likelihood of suicidal thoughts, and participants presenting psychiatric disorders were twice as likely to demonstrate suicidal ideation as those who did not. Alcohol dependence, alcohol craving and psychiatric comorbidity may be regarded as risk factors for suicidal ideation in the studied sample, with the only protective factor being living in a relationship.

Monte Carlo-based investigations on the impact of removing the flattening filter on beam quality specifiers for photon beam dosimetry.

PURPOSE: The impact of removing the flattening filter in clinical electron accelerators on the relationship between dosimetric quantities such as beam quality specifiers and the mean photon and electron energies of the photon radiation field was investigated by Monte Carlo simulations. The purpose of this work was to determine the uncertainties when using the well-known beam quality specifiers or energy-based beam specifiers as predictors of dosimetric photon field properties when removing the flattening filter. METHODS: Monte Carlo simulations applying eight different linear accelerator head models with and without flattening filter were performed in order to generate realistic radiation sources and calculate field properties such as restricted mass collision stopping power ratios (L¯/ρ)airwater, mean photon and secondary electron energies. To study the impact of removing the flattening filter on the beam quality correction factors kQ , this factor for detailed ionization chamber models was calculated by Monte Carlo simulations. Stopping power ratios (L¯/ρ)airwater and kQ values for different ionization chambers as a function of TPR1020 and %dd(10)x were calculated. Moreover, mean photon energies in air and at the point of measurement in water as well as mean secondary electron energies at the point of measurement were calculated. RESULTS: The results revealed that removing the flattening filter led to a change within 0.3% in the relationship between %dd(10)x and (L¯/ρ)airwater, whereby the relationship between TPR1020 and (L¯/ρ)airwater changed up to 0.8% for high energy photon beams. However, TPR1020 was a good predictor of (L¯/ρ)airwater for both types of linear accelerator with energies < 10 MeV with a maximal deviation between both types of accelerators of 0.23%. According to the results, the mean photon energy below the linear accelerators head as well as at the point of measurement may not be suitable as a predictor of (L¯/ρ)airwater and kQ to merge the dosimetry of both linear accelerator types. It was possible to derive (L¯/ρ)airwater using the mean secondary electron energy at the point of measurement as a predictor with an accuracy of 0.17%. A bias between kQ for linear accelerators with and without flattening filter within 1.1% and 1.6% was observed for TPR1020 and %dd(10)x respectively. CONCLUSION: The results of this study have shown that removing the flattening filter led to a change in the relationship between the well-known beam quality specifiers and dosimetric quantities at the point of measurement, namely (L¯/ρ)airwater, mean photon and electron energy. Furthermore, the results show that a beam profile correction is important for dose measurements with large ionization chambers in flattening filter free beams.

EURADOS intercomparison exercise on Monte Carlo modelling of a medical linear accelerator.

BACKGROUND: In radiotherapy, Monte Carlo (MC) methods are considered a gold standard to calculate accurate dose distributions, particularly in heterogeneous tissues. EURADOS organized an international comparison with six participants applying different MC models to a real medical linear accelerator and to one homogeneous and four heterogeneous dosimetric phantoms. AIMS: The aim of this exercise was to identify, by comparison of different MC models with a complete experimental dataset, critical aspects useful for MC users to build and calibrate a simulation and perform a dosimetric analysis. RESULTS: Results show on average a good agreement between simulated and experimental data. However, some significant differences have been observed especially in presence of heterogeneities. Moreover, the results are critically dependent on the different choices of the initial electron source parameters. CONCLUSIONS: This intercomparison allowed the participants to identify some critical issues in MC modelling of a medical linear accelerator. Therefore, the complete experimental dataset assembled for this intercomparison will be available to all the MC users, thus providing them an opportunity to build and calibrate a model for a real medical linear accelerator.

Blood glucose and lipid concentrations after overload are not associated with the risk of alcohol relapse.

AIMS: There is evidence for the functioning of feedback between alcohol consumption and fat (positive) and carbohydrate (negative) intake. We tried to verify the hypothesis that blood glucose and lipid concentration in a fasting state and after loading may affect the risk of relapse in alcohol-dependent male patients during withdrawal therapy. METHODS: Blood glucose, total cholesterol (TC) and triglycerides (TG) were determined at the beginning of the study, and again after 4 weeks and 6 months of observation in 54 alcohol-dependent male patients treated against drinking relapse. Glucose concentration was checked after fasting and 2h after loading with a 75 g water solution of glucose, and blood lipids were determined on an empty stomach and 5h after butter loading (0.5 g of butter per kilogram of body mass). RESULTS: Patients who relapsed compared to subjects who remained abstinent during the 6-month observation did not differ significantly in relation to blood glucose, TC or TG blood concentrations, either in a fasting state or after loading. Patients with an initial above-median increase in TG blood concentration after butter loading (>38%) before the beginning of the study, and who smoked cigarettes with a greater content of nicotine and tar, preferred vodka and had lower values of aminotransferases. CONCLUSION: Fasting and postprandial blood glucose, TC and TG concentrations had no relationship with the outcome of anti-relapse treatment. However, they presented some associations with the pathomechanism of addiction to nicotine.