Using dispersion models at microscale to assess long-term air pollution in urban hot spots: A FAIRMODE joint intercomparison exercise for a case study in Antwerp.

In the framework of the Forum for Air Quality Modelling in Europe (FAIRMODE), a modelling intercomparison exercise for computing NO2 long-term average concentrations in urban districts with a very high spatial resolution was carried out. This exercise was undertaken for a district of Antwerp (Belgium). Air quality data includes data recorded in air quality monitoring stations and 73 passive samplers deployed during one-month period in 2016. The modelling domain was 800 × 800 m2. Nine modelling teams participated in this exercise providing results from fifteen different modelling applications based on different kinds of model approaches (CFD - Computational Fluid Dynamics-, Lagrangian, Gaussian, and Artificial Intelligence). Some approaches consisted of models running the complete one-month period on an hourly basis, but most others used a scenario approach, which relies on simulations of scenarios representative of wind conditions combined with post-processing to retrieve a one-month average of NO2 concentrations. The objective of this study is to evaluate what type of modelling system is better suited to get a good estimate of long-term averages in complex urban districts. This is very important for air quality assessment under the European ambient air quality directives. The time evolution of NO2 hourly concentrations during a day of relative high pollution was rather well estimated by all models. Relative to high resolution spatial distribution of one-month NO2 averaged concentrations, Gaussian models were not able to give detailed information, unless they include building data and street-canyon parameterizations. The models that account for complex urban geometries (i.e. CFD, Lagrangian, and AI models) appear to provide better estimates of the spatial distribution of one-month NO2 averages concentrations in the urban canopy. Approaches based on steady CFD-RANS (Reynolds Averaged Navier Stokes) model simulations of meteorological scenarios seem to provide good results with similar quality to those obtained with an unsteady one-month period CFD-RANS simulations.

Successful Minority Representations on TV Count: A Quantitative Content Analysis Approach.

Numerous studies provide critical analyses of TV minority representations but only few examine successful portrayals. Moreover, there is no consensus on what makes a given depiction successful and how to measure it. Bringing insights from representation studies and media psychology, we propose that successful representations showcase minorities in a way which may foster audience engagement with characters and improve their diversity attitudes. In the current project, we developed a quantitative content analysis codebook with the following representation strategies: portrayal of minority experiences, recognizable representation, attractive representation, psychological depth, stereotypical representation, and friendly interactions. We demonstrate our approach by analyzing the portrayal of non-heterosexual and Black characters in Sex Education. We coded all the scenes with Eric, Adam, and Jackson from the first season of the TV show. Results indicate that these characters are predominantly shown as recognizable to viewers and in friendly interactions with other people. Moreover, they are depicted with attractive personality traits, and indicators of psychological depth. They also undergo various minority experiences. Some stereotypes about gay men are shown but anti-Black stereotypes are rare. In the results' discussion, we suggest different ways of using our codebook in future studies.

[Nontuberculous mycobacterial infection after tattooing caused by Mycobacterium chelonae]. / Nichttuberkulöse Mykobakteriose nach Tätowierung durch Mycobacterium chelonae.

We report the case of a healthy young man who presented to our clinic with itchy skin lesions in the area of a tattoo on the back of the left hand. Bioptic and cultural confirmation of the pathogens led to the diagnosis of Mycobacterium chelonae infection. We initiated antibiotic therapy using azithromycin and linezolid with good response. Our case underlines that besides allergic skin reactions, infections as a complication after tattooing should also be included in the differential diagnosis.

Test-retest reliability, construct validity and determinants of 6-minute walk test performance in adult patients with asthma.

INTRODUCTION AND OBJECTIVES: Current knowledge regarding the measurement properties of the 6-minute walk test (6MWT) in patients with asthma is limited. Therefore, the aim of this study was to assess the test-retest reliability, measurement error and construct validity of the 6MWT and identify determinants of 6-minute walk distance (6MWD) in patients with asthma. PATIENTS AND METHODS: 201 asthma patients referred for pre-pulmonary rehabilitation assessment, were retrospectively analyzed (age 61±12 years, 42% male, FEV1 78±27% predicted). Patients performed two 6MWTs on subsequent days using a 30 m straight walking course. Other measurements included resting dyspnea, maximal exercise capacity, body composition, pulmonary function, pulmonary and quadriceps muscle strength and symptoms of anxiety and depression. Measurement error (absolute reliability) was tested using standard error of measurement (SEM), minimal detectable change at 95% confidence interval (MDC95%) and Bland and Altman 95% limits of agreement, whereas test-retest reliability (relative reliability) and construct validity were assessed using the intra-class correlation coefficient (ICC2,1) and correlations, respectively. RESULTS: The 6MWD showed excellent test-retest reliability (ICC2,1: 0.91). The mean change in 6MWD after the second 6MWT was 18m (95%CI 11-24m), with 73% of the patients walking further in the second test. The SEM and MDC95% for the 6MWT were 35 m and 98 m, respectively. The best 6MWD correlated strongly with peak oxygen uptake during CPET and resting dyspnea (r = 0.61-0.64) and had no-to-moderate correlations with body composition, pulmonary function, respiratory and quadriceps muscle strength and symptoms of anxiety and depression (r = 0.02-0.45). Multiple linear regression was able to identify maximal workload, BMI, rollator use, maximal expiratory pressure, FEV1 and DLCO as independent determinants of the best 6MWD (R2 = 0.58). CONCLUSIONS: The 6MWT was considered to be reliable and valid in patients with asthma, which strengthens its clinical utility. However, the majority of patients demonstrated a considerable learning effect in the second 6MWT, providing a strong rationale for performing two 6MWTs.

Short- and long-term impact of cancer on employment and financial outcomes of adolescents and young adults (AYAs): a large population-based case-control registry study in the Netherlands.

BACKGROUND: Adolescent and young adult (AYA) cancer survivors, 18-39 years at initial cancer diagnosis, often self-report negative consequences of cancer (treatment) for their career. Less is known, however, about the objective impact of cancer on employment and financial outcomes. This study examines the employment and financial outcomes of AYA cancer survivors with nationwide population-based registry data and compares the outcomes of AYAs with cancer with an age- and sex-matched control population at year of diagnosis, 1 year later (short-term) and 5 years later (long-term). PATIENTS AND METHODS: A total of 2527 AYAs, diagnosed in 2013 with any invasive tumor type and who survived for 5 years, were identified from the Netherlands Cancer Registry (clinical and demographic data) and linked to Statistics Netherlands (demographic, employment and financial data). AYAs were matched 1 : 4 with a control population based on age and sex (10 108 controls). Analyses included descriptive statistics, chi-square tests, independent samples t-tests, McNemar tests and logistic regression. RESULTS: AYA cancer survivors were significantly less often employed compared with their controls 1 year (76.1% versus 79.5%, P < 0.001) and 5 years (79.3% versus 83.5%, P < 0.001) after diagnosis, and received more often disability benefits (9.9% versus 3.1% 1 year after diagnosis, P < 0.001; 11.2% versus 3.8% 5 years after diagnosis, P < 0.001). Unemployed AYAs were more often diagnosed with higher disease stages (P < 0.001), treated with chemotherapy (P < 0.001), radiotherapy (P < 0.001) or hormone therapy (P < 0.05) and less often with local surgery (P < 0.05) compared with employed AYAs 1 and 5 years after diagnosis. CONCLUSION: Based on objective, nationwide, population-based registry data, AYAs' employment and financial outcomes are significantly affected compared with age- and sex-matched controls, both short and long-term after cancer diagnosis. Providing support regarding employment and financial outcomes from diagnosis onwards may help AYAs finding their way (back) into society.

[Bullous pemphigoid with unilateral sparing after axillary lymphadenectomy]. / Bullöses Pemphigoid mit Aussparung eines Armes nach axillärer Lymphadenektomie.

An 83-year-old woman presented to our outpatient clinic with bullous pemphigoid with a unilateral sparing of the left arm after axillary lymphadenectomy because of breast cancer. Cases of localized manifestations of bullous pemphigoid are mainly caused by lymphedema or radiation. The absence of blistering after lymphadenectomy is a rare and interesting manifestation. Pathophysiologically, blister formation may be attenuated or absent altogether due to decreased T­cell activation and thus reduced inflammatory infiltrate because of the absence of peripheral lymph nodes.

Visual cues added to a virtual environment paradigm do not improve motor arrests in Parkinson's disease.

Objective. Elucidating how cueing alleviates freezing of gait (FOG) in Parkinson's disease (PD) would enable the development of more effective, personalized cueing strategies. Here, we aimed to validate a visual cueing virtual environment (VE) paradigm for future use in e.g. neuroimaging studies and behavioral studies on motor timing and scaling in PD patients with FOG.Approach. We included 20 PD patients with FOG and 16 age-matched healthy control subjects. Supine participants were confronted with a VE displaying either no cues, bars or staircases. They navigated forward using alternate suppression of foot pedals. Motor arrests (as proxy for FOG), and measures of motor timing and scaling were compared across the three VE conditions for both groups.Main results. VE cues (bars and staircases) did not reduce motor arrests in PD patients and healthy control subjects. The VE cues did reduce pedal amplitude in healthy control subjects, without effects on other motor parameters.Conclusion. We could not validate a visual cueing VE paradigm to study FOG. The VE cues possibly failed to convey the necessary spatial and temporal information to support motor timing and scaling. We discuss avenues for future research.

Dusseldorf autopsies 1914-1918.

This article presents an evaluation of 4255 autopsy cases recorded at the Dusseldorf Pathology Institute in the years 1914 to 1918. Diagnoses were coded according to the International Classification of Diseases, 10th edition (ICD-10), and the contemporaneous history of the Pathology Institute was reviewed. We found a proportion of 54.1% adults and 45.5% children in our cohort, with a male predominance of 63.9%. Infectious diseases account for the majority of all cases (35.5%), among which tuberculosis is the most frequent, reported in 22.7% of all cases. The second largest diagnosis group is the one of respiratory diseases (16.9%), including pneumonia and influenza. Cases of perinatal conditions account for 10.5% of the collective, followed by neoplasms, injuries, intoxications, or external causes, each representing 6.6%. Cardiovascular diseases account for 5.3% of the cases. In 4.4% of the pediatric and 0.8% of adult cases, a diagnosis of the ICD-10 group "nutritional and endocrine diseases" was made. No diagnosis of hunger edema is reported. Parts of the cohort are 272 war pathology cases (6.4%), made up by soldiers who mainly had died of shotgun injuries. The whole cohort represents the disease spectrum of a German big city population at times of World War I. The data exemplify the epidemiological shift that has occurred in industrialized countries over the last 100 years, from infectious to neoplastic and cardiovascular diseases.

Cost-effectiveness of stress CTP versus CTA in detecting obstructive CAD or in-stent restenosis in stented patients.

OBJECTIVES: The aim of this retrospective study was to determine cost-effectiveness of stress myocardial CT perfusion (CTP), coronary CT angiography (CTA), and the combination of both in suspected obstructive coronary artery disease (CAD) or in-stent restenosis (ISR) in patients with previous coronary stent implantation. METHODS: A decision model based on Markov simulations estimated lifetime costs and quality-adjusted life years (QALYs) associated with CTA, CTP, and CTA + CTP. Model input parameters were obtained from published literature. Probabilistic sensitivity analysis was performed to evaluate overall model uncertainty. A single-variable deterministic sensitivity analysis evaluated the sensitivity of the results to plausible variations in model inputs. Cost-effectiveness was assessed based on a cost-effectiveness threshold of $100,000 per QALY. RESULTS: In the base-case scenario with willingness to pay of $100,000 per QALY, CTA resulted in total costs of $47,013.87 and an expected effectiveness of 6.84 QALYs, whereas CTP resulted in total costs of $46,758.83 with 6.93 QALYs. CTA + CTP reached costs of $47,455.63 with 6.85 QALYs. Therefore, strategies CTA and CTA + CTP were dominated by CTP in the base-case scenario. Deterministic sensitivity analysis demonstrated robustness of the model to variations of diagnostic efficacy parameters and costs in a broad range. CTP was cost-effective in the majority of iterations in the probabilistic sensitivity analysis as compared with CTA. CONCLUSIONS: CTP is cost-effective for the detection of obstructive CAD or ISR in patients with previous stenting and therefore should be considered a feasible approach in daily clinical practice. KEY POINTS: • CTP provides added diagnostic value in patients with previous coronary stents. • CTP is a cost-effective method for the detection of obstructive CAD or ISR in patients with previous stenting.

Sparing the hippocampus and the hypothalamic- pituitary region during whole brain radiotherapy: a volumetric modulated arc therapy planning study.

BACKGROUND: Feasibility testing of a simultaneous sparing approach of hippocampus, hypothalamus and pituitary gland in patients undergoing whole-brain radiotherapy (WBRT) with and without a concomitant boost to metastatic sites. INTRODUCTION: Cognitive impairment and hormonal dysfunction are common side effects of cranial radiotherapy. A reduced dose application to the patho-physiologically involved functional brain areas, i.e. hippocampus, hypothalamus and pituitary gland, could reduce these common side effects. While hippocampal sparing is already a common practice to improve cognitive outcome, technical experience of additional combined sparing of the hypothalamus/pituitary gland (HT-P) is insufficient. METHODS: Twenty patients were included in the planning study. In 11 patients, a total dose of 36 Gy of WBRT (2 Gy per fraction) plus a simultaneous integrated boost (SIB) of 9 Gy (0.5 Gy per fraction, total dose: 45 Gy) to the brain metastases was applied. In 9 patients, prophylactic cranial irradiation (PCI) was simulated with a total dose of 30 Gy (2 Gy per fraction). In both patient cohorts, a sparing approach of the hippocampus and the HT-P area was simulated during WBRT. For all treatment plans, volumetric modulated arc therapy (VMAT) was used. Quality assurance included assessment of homogeneity, conformality and target coverage. RESULTS: The mean dose to the hippocampus and HT-P region was limited to less than 50% of the prescribed dose to the planning target volume (PTV) in all treatment plans. Dose homogeneity (HI) of the target volume was satisfying (median HI = 0.16 for WBRT+SIB and 0.1 for PCI) and target coverage (conformation number, CN) was not compromised (median CN = 0.82 for SIB and 0.86 for PCI). CONCLUSION: Simultaneous dose reduction to the hippocampus and the HT-P area did not compromise the PTV coverage in patients undergoing WBRT+SIB or PCI using VMAT. While the feasibility of the presented approach is promising, prospective neurologic, endocrine outcome and safety studies are required.

[Dutch guideline on necrotizing soft tissue infections]. / Richtlijn 'Necrotiserende wekedeleninfecties'.

In 2018 the first Dutch guideline on necrotizing soft tissue infections (NSTIs) was drafted. Its aim is to standardize the care of this disease in order to reduce variation, and thereby improve the quality of care. This guideline is a benchmark for all healthcare providers who deal with this devastating disease; it focuses on diagnostics, treatment options and organization of care. Given the low incidence, the complexity and the fulminant course of NSTIs, it is important to ensure continuous specialized care. Therefore it is recommended to make regional agreements about referral to specialized centres. Surgical exploration remains the gold standard for diagnosis. The empirical antibiotic regimen depends on if the onset of disease is community or nosocomial, and if its aetiology is a monomicrobial (type I) or a polymicrobial (type II). The guideline recommends that intravenous immunoglobulin (IVIg) therapy be started if gram staining reveals streptococci. IVIg must be discontinued if group-A streptococcus is excluded as a causative agent.

Are hypothalamic- pituitary (HP) axis deficiencies after whole brain radiotherapy (WBRT) of relevance for adult cancer patients? - a systematic review of the literature.

BACKGROUND: Cranial radiotherapy (cRT) can induce hormonal deficiencies as a consequence of significant doses to the hypothalamic-pituitary (HP) axis. In contrast to profound endocrinological follow-up data from survivors of childhood cancer treated with cRT, little knowledge exists for adult cancer patients. METHODS: A systematic search of the literature was conducted using the PubMed database and the Cochrane library offering the basis for our debate of the relevance of HP axis impairment after cRT in adult cancer patients. Against the background of potential relevance for patients receiving whole brain radiotherapy (WBRT), a particular focus was set on the temporal onset of hypopituitarism and the radiation dose to the HP axis. RESULTS: Twenty-eight original papers with a total of 1728 patients met the inclusion criteria. Radiation doses to the HP area ranged from 4 to 97 Gray (Gy). Hypopituitarism incidences ranged from 20 to 93% for adult patients with nasopharyngeal cancer or non-pituitary brain tumors. No study focused particularly on hypopituitarism after WBRT. The onset of hypopituitarism occurred as early as within the first year following cRT (range: 3 months to 25.6 years). However, since most studies started follow-up evaluation only several years after cRT, early onset of hypopituitarism might have gone unnoticed. CONCLUSION: Hypopituitarism occurs frequently after cRT in adult cancer patients. Despite the general conception that it develops only after several years, onset of endocrine sequelae can occur within the first year after cRT without a clear threshold. This finding is worth debating particularly in respect of treatment options for patients with brain metastases and favorable survival prognoses.

Systematic review of interventions in the childcare setting with direct parental involvement: effectiveness on child weight status and energy balance-related behaviours.

BACKGROUND: The early years are a crucial period to promote healthy energy balance-related behaviours in children and prevent overweight and obesity. The childcare setting is important for health-promoting interventions. Increasingly, attention has been paid to parental involvement in childcare-based interventions. The aim of this systematic review is to evaluate the effectiveness of these interventions with direct parental involvement on the children's weight status and behavioural outcomes. METHODS: A systematic search was conducted in four electronic databases to include studies up until January 2019. Studies written in English, describing results on relevant outcomes (weight status, physical activity, sedentary behaviour and/or nutrition-related behaviour) of childcare-based interventions with direct parental involvement were included. Studies not adopting a pre-post-test design or reporting on pilot studies were excluded. To improve comparability, effect sizes (Cohen's d) were calculated. Information on different types of environment targeted (e.g., social, physical, political and economic) was extracted in order to narratively examine potential working principles of effective interventions. RESULTS: A total of 22 studies, describing 17 different interventions, were included. With regard to the intervention group, 61.1% found some favourable results on weight status, 73.3% on physical activity, 88.9% on sedentary behaviour, and all on nutrition-related behaviour. There were studies that also showed unfavourable results. Only a small number of studies was able to show significant differences between the intervention and control group (22.2% weight status, 60.0% physical activity, 66.6% sedentary behaviour, 76.9% nutrition behaviour). Effect sizes, if available, were predominantly small to moderate, with some exceptions with large effect sizes. The interventions predominantly targeted the socio-cultural and physical environments in both the childcare and home settings. Including changes in the political environment in the intervention and a higher level of intensity of parental involvement appeared to positively impact intervention effectiveness. CONCLUSION: Childcare-based interventions with direct parental involvement show promising effects on the children's energy balance-related behaviours. However, evidence on effectiveness is limited, particularly for weight-related outcomes. Better understanding of how to reach and involve parents may be essential for strengthening intervention effectiveness.

Baby's first bites: a randomized controlled trial to assess the effects of vegetable-exposure and sensitive feeding on vegetable acceptance, eating behavior and weight gain in infants and toddlers.

BACKGROUND: The start of complementary feeding in infancy plays an essential role in promoting healthy eating habits. Evidence shows that it is important what infants are offered during this first introduction of solid foods: e.g. starting exclusively with vegetables is more successful for vegetable acceptance than starting with fruits. How infants are introduced to solid foods also matters: if parents are sensitive and responsive to infant cues during feeding, this may promote self-regulation of energy intake and a healthy weight. However, the effectiveness of the what and the how of complementary feeding has never been experimentally tested in the same study. In the current project the what and how (and their combination) are tested in one study to determine their relative importance for fostering vegetable acceptance and self-regulation of energy intake in infants. METHODS: A four-arm randomized controlled trial (Baby's First Bites (BFB)) was designed for 240 first-time Dutch mothers and their infants, 60 per arm. In this trial, we compare the effectiveness of (a) a vegetable-exposure intervention focusing on the what in complementary feeding; (b) a sensitive feeding intervention focusing on the how in complementary feeding, (c) a combined intervention focusing on the what and how in complementary feeding; (d) an attention-control group. All mothers participate in five sessions spread over the first year of eating solid foods (child age 4-16 months). Primary outcomes are vegetable consumption, vegetable liking and self-regulation of energy intake. Secondary outcomes are child eating behaviors, child anthropometrics and maternal feeding behavior. Outcomes are assessed before, during and directly after the interventions (child age 18 months), and when children are 24 and 36 months old. DISCUSSION: The outcomes are expected to assess the impact of the interventions and provide new insights into the mechanisms underlying the development of vegetable acceptance, self-regulation and healthy eating patterns in infants and toddlers, as well as the prevention of overweight. The results may be used to improve current dietary advice given to parents of their young children on complementary feeding. TRIAL REGISTRATION: The trial was retrospectively registered during inclusion of participants at the Netherlands National Trial Register (identifier NTR6572 ) and at ClinicalTrials.gov ( NCT03348176 ). Protocol issue date: 1 April 2018; version number 1.

Validation of the Auditory Stroop Task to increase cognitive load in walking tasks in healthy elderly and persons with Parkinson's disease.

BACKGROUND: The development of treatments for freezing of gait (FOG) in Parkinson's disease (PD) requires experimental study set-ups in which FOG is likely to occur, and is amenable to therapeutic interventions. We explore whether the 'Auditory Stroop Task' (AST) can be used to increase cognitive load (and thereby elicit FOG), simultaneously with visual cues (as a therapeutic intervention for FOG). We additionally examined how these two contrasting effects might interact in affecting gait and FOG parameters. OBJECTIVES: We investigated whether: (1) the 'Auditory Stroop Task' (AST) influences gait in healthy elderly and persons with PD who experience FOG, and increases the frequency of FOG events among PD patients; (2) the AST and visual cues interact; and (3) different versions of the AST exert different cognitive loads. METHODS: In 'Experiment 1', 19 healthy elderly subjects performed a walking task while performing a high and low load version of the AST. Walking with a random numbers task, and walking without cognitive load served as control conditions. In 'Experiment 2', 20 PD patients with FOG and 18 healthy controls performed a walking task with the AST, and no additional cognitive load as control condition. Both experiments were performed with and without visual cues. Velocity, cadence, stride length, and stride time were measured in all subjects. FOG severity was measured in patients. RESULTS: Compared to the control conditions, the AST negatively affected all gait parameters in both patients and controls. The AST did not increase the occurrence of FOG in patients. Visual cues reduced the decline in stride length induced by cognitive load in both groups. Both versions of the AST exerted similar effects on gait parameters in controls. CONCLUSIONS: The AST is well-suited to simulate the effects of cognitive load on gait parameters, but not FOG severity, in gait experiments in persons with PD and FOG.

Source apportionment to support air quality planning: Strengths and weaknesses of existing approaches.

Information on the origin of pollution constitutes an essential step of air quality management as it helps identifying measures to control air pollution. In this work, we review the most widely used source-apportionment methods for air quality management. Using theoretical and real-case datasets we study the differences among these methods and explain why they result in very different conclusions to support air quality planning. These differences are a consequence of the intrinsic assumptions that underpin the different methodologies and determine/limit their range of applicability. We show that ignoring their underlying assumptions is a risk for efficient/successful air quality management as these methods are sometimes used beyond their scope and range of applicability. The simplest approach based on increments (incremental approach) is often not suitable to support air quality planning. Contributions obtained through mass-transfer methods (receptor models or tagging approaches built in air quality models) are appropriate to support planning but only for specific pollutants. Impacts obtained via "brute-force" methods are the best suited but it is important to assess carefully their application range to make sure they reproduce correctly the prevailing chemical regimes.

Supporting the improvement of air quality management practices: The "FAIRMODE pilot" activity.

This paper presents the first outcomes of the "FAIRMODE pilot" activity, aiming at improving the way in which air quality models are used in the frame of the European "Air Quality Directive". Member States may use modelling, combined with measurements, to "assess" current levels of air quality and estimate future air quality under different scenarios. In case of current and potential exceedances of the Directive limit values, it is also requested that they "plan" and implement emission reductions measures to avoid future exceedances. In both "assessment" and "planning", air quality models can and should be used; but to do so, the used modelling chain has to be fit-for-purpose and properly checked and verified. FAIRMODE has developed in the recent years a suite of methodologies and tools to check if emission inventories, model performance, source apportionment techniques and planning activities are fit-for-purpose. Within the "FAIRMODE pilot", these tools are used and tested by regional/local authorities, with the two-fold objective of improving management practices at regional/local scale, and providing valuable feedback to the FAIRMODE community. Results and lessons learnt from this activity are presented in this paper, as a showcase that can potentially benefit other authorities in charge of air quality assessment and planning.

Radiotherapy for prostate cancer: DISCERN quality assessment of patient-oriented websites in 2018.

BACKGROUND: Prostate cancer is the most commonly diagnosed cancer in men. Radiotherapy represents one major treatment option in different therapeutic settings. As patients increasingly rely on internet-based medical information, we examined the quality of information on radiotherapy and prostate cancer in websites used by laypersons. METHODS: An Internet search from a patients` perspective was carried out using different search engines (Google, Yahoo and Bing, search terms: "prostate cancer" and "radiotherapy"). The quality of search results was analyzed with regard to the DISCERN score, HON code certification, the JAMA criteria and the ALEXA traffic rank. RESULTS: In general, websites were of good quality. The highest quality was found for websites operated by charity organizations. No significant differences in results obtained via the above-mentioned tools were seen for the examined search engines, but Google revealed the most stable search results in terms of temporal changes. CONCLUSION: Patients with prostate cancer can sufficiently inform themselves on general treatment options including radiotherapy on websites directed at laypersons. However, no simple strategy could identify high quality websites in general. For treating physicians, it is important to support patients in interpreting and ranking the vast quantity of information.