Body-weight dependent dose coefficients for adults exposed to idealised external photon fields.

In epidemiological investigations of cancer risk from occupational exposure, it is important to obtain an organ-specific dose for each cohort member for accurate risk analysis. To date, dose conversion coefficients, which convert physical dose measurement to organ dose, are only available for individuals with reference body size, which can differentially bias the estimated organ dose depending on the body mass index of cohort members. In the current study, we calculated the organ dose coefficients applicable to adult males and females with various body weights by using the Monte Carlo radiation transport technique combined with a library of body size-dependent hybrid computational phantoms exposed in six idealised irradiation geometries. We adapted the eight adult male phantoms, 175 cm tall with weights of 60, 70, 80, 90, 100, 110, 120 and 130 kg, and the nine adult female phantoms, 165 cm tall with weights of 50, 60, 70, 80, 90, 100, 110, 120 and 130 kg. The radiation transport was simulated using MCNPX 2.7 Monte Carlo code. Phantoms were irradiated by external photon fields in anterior posterior (AP), posterior-anterior, right and left lateral, rotational, and isotropic geometries. The results showed that the 60 kg adult male phantom shows 1.33-, 1.43-, 1.44- and 1.52-fold greater dose coefficients for the lungs, heart, stomach, and liver, respectively, than the 120 kg adult male phantom at 0.1 MeV in AP geometry. We derived exponential correlation between organ dose coefficients and body weight to facilitate calculation of organ dose coefficients for a given weight. The comprehensive organ dose coefficients and exponential regression model can be used to estimate more accurate organ dose for individuals of the two genders with various body weights exposed to external photon radiation.

Assessment of thyroid cancer risk associated with radiation dose from personal diagnostic examinations in a cohort study of US radiologic technologists, followed 1983-2014.

OBJECTIVE: To assess whether personal medical diagnostic procedures over life, but particularly those associated with exposure in adulthood, were associated with increased thyroid cancer risk. DESIGN: Participants from the US Radiologic Technologists Study, a large, prospective cohort, were followed from the date of first mailed questionnaire survey completed during 1983-1989 to the earliest date of self-reported diagnosis of thyroid cancer or of any other cancer than non-melanoma skin cancer (NMSC) in any of three subsequent questionnaires up to the last in 2012-2014. SETTING: US nationwide, occupational cohort. PARTICIPANTS: US radiologic technologists with exclusion of: those who reported a previous cancer apart from NMSC on the first questionnaire; those who reported a cancer with an unknown date of diagnosis on any of the questionnaires; and those who did not respond to both the first questionnaire and at least one subsequent questionnaire. PRIMARY OUTCOME MEASURE: We used Cox proportional hazards models with age as timescale to compute HRs and 95% CI for thyroid cancer in relation to cumulative 5-year lagged diagnostic thyroid dose. RESULTS: There were 414 self-reported thyroid cancers (n=275 papillary) in a cohort of 76 415 persons. Cumulative thyroid dose was non-significantly positively associated with total (excess relative risk/Gy=2.29 (95% CI -0.91 to 7.01, p=0.19)) and papillary thyroid cancer (excess relative risk/Gy=4.15 (95% CI -0.39, 11.27, p=0.08)) risk. These associations were not modified by age at, or time since, exposure and were independent of occupational exposure. CONCLUSION: Our study provides weak evidence that thyroid dose from diagnostic radiation procedures over the whole of life, in particular associated with exposure in adulthood, influences adult thyroid cancer risk.

Thyroid Radiation Dose to Patients from Diagnostic Radiology Procedures over Eight Decades: 1930-2010.

This study summarizes and compares estimates of radiation absorbed dose to the thyroid gland for typical patients who underwent diagnostic radiology examinations in the years from 1930 to 2010. The authors estimated the thyroid dose for common examinations, including radiography, mammography, dental radiography, fluoroscopy, nuclear medicine, and computed tomography (CT). For the most part, a clear downward trend in thyroid dose over time for each procedure was observed. Historically, the highest thyroid doses came from the nuclear medicine thyroid scans in the 1960s (630 mGy), full-mouth series dental radiography (390 mGy) in the early years of the use of x rays in dentistry (1930s), and the barium swallow (esophagram) fluoroscopic exam also in the 1930s (140 mGy). Thyroid uptake nuclear medicine examinations and pancreatic scans also gave relatively high doses to the thyroid (64 mGy and 21 mGy, respectively, in the 1960s). In the 21st century, the highest thyroid doses still result from nuclear medicine thyroid scans (130 mGy), but high thyroid doses are also associated with chest/abdomen/pelvis CT scans (18 and 19 mGy for males and females, respectively). Thyroid doses from CT scans did not exhibit the same downward trend as observed for other examinations. The largest thyroid doses from conventional radiography came from cervical spine and skull examinations. Thyroid doses from mammography (which began in the 1960s) were generally a fraction of 1 mGy. The highest average doses to the thyroid from mammography were about 0.42 mGy, with modestly larger doses associated with imaging of breasts with large compressed thicknesses. Thyroid doses from dental radiographic procedures have decreased markedly throughout the decades, from an average of 390 mGy for a full-mouth series in the 1930s to an average of 0.31 mGy today. Upper GI series fluoroscopy examinations resulted in up to two orders of magnitude lower thyroid doses than the barium swallow. There are considerable uncertainties associated with the presented doses, particularly for characterizing exposures of individual identified patients. Nonetheless, the tabulations provide the only comprehensive report on the estimation of typical radiation doses to the thyroid gland from medical diagnostic procedures over eight decades (1930-2010). These data can serve as a resource for epidemiologic studies that evaluate the late health effects of radiation exposure associated with diagnostic radiologic examinations.

Dose coefficients for ICRP reference pediatric phantoms exposed to idealised external gamma fields.

Organ and effective dose coefficients have been calculated for the International Commission on Radiological Protection (ICRP) reference pediatric phantoms externally exposed to mono-energetic photon radiation (x- and gamma-rays) from 0.01 to 20 MeV. Calculations used Monte Carlo radiation transport techniques. Organ dose coefficients, i.e., organ absorbed dose per unit air kerma (Gy/Gy), were calculated for 28 organs and tissues including the active marrow (or red bone marrow) for 10 phantoms (newborn, 1 year, 5 year, 10 year, and 15 year old male and female). Radiation exposure was simulated for 33 photon mono-energies (0.01-20 MeV) in six irradiation geometries: antero-posterior (AP), postero-anterior, right lateral, left lateral, rotational, and isotropic. Organ dose coefficients for different ages closely agree in AP geometry as illustrated by a small coefficient of variation (COV) (the ratio of the standard deviation to the mean) of 4.4% for the lungs. The small COVs shown for the effective dose and AP irradiation geometry reflect that most of the radiosensitive organs are located in the front part of the human body. In contrast, we observed differences in organ dose coefficients across the ages of the phantoms for lateral irradiation geometries. We also observed variation in dose coefficients across different irradiation geometries, where the COV ranges from 18% (newborn male) to 38% (15 year old male) across idealised whole body irradiation geometries for the major organs (active marrow, colon, lung, stomach wall, and breast) at the energy of 0.1 MeV. Effective dose coefficients were also derived for applicable situations, e.g., radiation protection or risk projection. Our results are the first comprehensive set of organ and effective dose coefficients applicable to children and adolescents based on the newly adopted ICRP pediatric phantom series. Our tabulated organ and effective dose coefficients for these next-generation phantoms should provide more accurate estimates of organ doses in children than earlier dosimetric models allowed.

Predictors of physicians' satisfaction with their management of uncertainty during a decision-making encounter with a simulated advanced stage cancer patient.

OBJECTIVES: To optimize their training, predictors of physicians' satisfaction with their management of uncertainty should be examined. This study investigated these predictors by using a simulated advanced stage cancer patient. METHODS: Physicians (n=85) rated their satisfaction with their management of uncertainty (Visual Analog Scale-100mm) after a decision-making encounter. Communication predictors were examined with the: Observing Patient Involvement scale (OPTION), Multidimensional analysis of Patient Outcome Predictions (MD.POP) and Communication Content Analysis Software (LaComm). Psychological predictors were assessed with the: Intolerance of Uncertainty Inventory (IUI), Physicians' Reactions to Uncertainty scale (PRU), Decisional Conflict Scale (DCS), and Jefferson Scale of Physician Empathy (JSPE). RESULTS: Physicians' satisfaction (mean=67mm; standard deviation=17mm) was not predicted by their communication, but by their anxiety due to uncertainty (PRU) (ß=-.42; p=<.001) and their perceived empathy (JSPE) (ß=.26; p=.009). These variables accounted for 25% of variance in physicians' satisfaction. CONCLUSIONS: Physicians' satisfaction with their management of uncertainty was not affected by their communication performance, but by their psychological characteristics. PRACTICE IMPLICATIONS: Training programs should increase physicians' awareness regarding the communication performance required in decision-making encounters under conditions of uncertainty.

[Breaking bad news in oncology: the Belgian experience]. / L'annonce de mauvaises nouvelles en oncologie: l'expérience belge.

Breaking bad news is a complex and frequent clinical task for physicians working in oncology. It can have a negative impact on patients and their relatives who are often present during breaking bad news consultations. Many factors influence how the delivery of bad news will be experienced especially the communication skills used by physicians. A three-phase process (post-delivery phase, delivery phase, pre-delivery phase) has been developed to help physician to handle this task more effectively. Communication skills and specific breaking bad news training programs are both necessary and effective. A recent study conducted in Belgium has shown their impact on the time allocated to each of the three phases of this process, on the communication skills used, on the inclusion of the relative in the consultation and on physicians' physiological arousal. These results underscore the importance of promoting intensive communication skills and breaking bad news training programs for health care professionals.

Is it possible to improve the breaking bad news skills of residents when a relative is present? A randomised study.

BACKGROUND: Although patients with cancer are often accompanied by a relative during breaking bad news (BBN) consultations, little is known regarding the efficacy of training programmes designed to teach residents the communication skills needed to break bad news in a triadic consultation. METHODS: Residents were randomly assigned to a 40-h dyadic and triadic communication skills training programme (n=48) or a waiting list (n=47). A simulated BBN triadic consultation was audiotaped at baseline, and after training for the training group, and 8 months after baseline for the waiting list group. Transcripts were analysed using content analysis software (LaComm). A coder determined the moment of bad news delivery and the relative's first turn of speech regarding the bad news. A generalised estimating equation was used to evaluate residents' communication skills, BBN timing, and the relative's inclusion in the consultation. RESULTS: Ninety-five residents were included. After training, the duration of the pre-delivery phase was found to be longer for the trained residents (relative risk (RR)=3.04; P<0.001). The simulated relative's first turn of speech about the bad news came more often during the pre-delivery phase (RR=6.68; P=0.008), and was more often initiated by the trained residents (RR=19.17; P<0.001). Trained residents also used more assessment (RR=1.83; P<0.001) and supportive utterances (RR=1.58; P<0.001). CONCLUSION: This study demonstrates that a training programme that focuses on the practice of dyadic and triadic communication skills can improve the communication skills of the participating residents in a BBN triadic consultation. Such a training should be included in resident curriculum.

Sludge drying reed beds for septage treatment: towards design and operation recommendations.

This paper focuses on the feasibility of septage treatment by sludge drying reed beds (SDRB). Different designs and operation conditions of SRDB pilot-scales were tested on system efficiencies such as the top filtration layer (sand or compost) and the organic load (30 and 50 kg SSm(-2)y(-1)). Results focus on the obtained performances considering sludge characteristics, filtration efficiencies, percolate qualities, and sludge deposit properties. Although results show better filtration efficiency for activated sludge (e.g. SS removal around 98.4%) than for septage (e.g. SS removal around 87.5%), the feasibility of septage treatment with SDRB has been demonstrated with, at 50 kg SSm(-2)y(-1) sludge accumulation, and dry matter about 7.9 cm y(-1) and 70% (summer period), respectively. Further design and operation condition recommendations for SDRB treating septage are proposed.

Is it possible to improve residents breaking bad news skills? A randomised study assessing the efficacy of a communication skills training program.

BACKGROUND: This study aims to assess the efficacy of a 40-h training programme designed to teach residents the communication skills needed to break the bad news. METHODS: Residents were randomly assigned to the training programme or to a waiting list. A simulated patient breaking bad news (BBN) consultation was audiotaped at baseline and after training in the training group and 8 months after baseline in the waiting-list group. Transcripts were analysed by tagging the used communication skills with a content analysis software (LaComm) and by tagging the phases of bad news delivery: pre-delivery, delivery and post-delivery. Training effects were tested with generalised estimating equation (GEE) and multivariate analysis of variance (MANOVA). RESULTS: The trained residents (n=50) used effective communication skills more often than the untrained residents (n=48): more open questions (relative rate (RR)=5.79; P<0.001), open directive questions (RR=1.71; P=0.003) and empathy (RR=4.50; P=0.017) and less information transmission (RR=0.72; P=0.001). The pre-delivery phase was longer for the trained (1 min 53 s at baseline and 3 min 55 s after training) compared with the untrained residents (2 min 7 s at baseline and 1 min 46 s at second assessment time; P<0.001). CONCLUSION: This study shows the efficacy of training programme designed to improve residents' BBN skills. The way residents break bad news may thus be improved.

Sludge drying reed beds: full- and pilot-scale study for activated sludge treatment.

Sludge drying reed beds have been used for dewatering and mineralization of sludge since the beginning of the 90s, but their insufficient performances in terms of Dry Matter [DM] content and mineralization of the sludge have made necessary new studies. Therefore, 8 pilots of 2 m2 each and a full-scale plant (13,000 p.e, 8 beds of 470 m2 in operation for 4 years) have been monitored to examine the influence of the sludge loading rate, the sludge quality and the loading frequency on the dewatering and mineralization efficiencies. Two filtration layers and two loading rhythms were tested on pilots which were fed at a loading rate of 25-30 kg DM m(-2) yr(-1) during the first year of operation (commissioning period). Hydraulic behaviour (infiltration rate, outflow), O2 and CO2 relative concentrations in the filtration media, redox potential, pollutants removal and dry matter content were assessed during all the study. The rheological quality of the extracted sludge from full scale beds was assessed and showed that its mechanical behaviour exceed those of sludge of comparable dry matter content, making its spreading easier. Therefore, this sludge could easily claim the status of solid and stabilized sludge according to the French regulation. Design and management recommendations (number of beds, loading rates, feeding/rest period) gained from the experiments results are suggested.

Treatment of septage in sludge drying reed beds: a case study on pilot-scale beds.

French legislation requires the control of private on-site sanitation systems by local authorities. This will result in a large increase of the quantity of sludge from septic tanks to be treated. Nevertheless, large wastewater treatment plants are not systematically able to treat this sludge because they may have reached their nominal load or they are not so numerous in rural zone to avoid too long transportation. The study concerns both the feasibility of sludge reed beds devoted to the treatment of septage and the assessment of a simultaneous treatment with aerated sludge. The experiments have been carried out on eight pilot-scale drying reed beds (2 m(2)) planted with Phragmites australis. Two filtration layers of either vegetal compost or sand were tested. The study is focused on the commissioning period (first vegetative year) with a loading rate of 30 kg SS m(-2) yr(-1). According to these operational conditions, dewatering efficiencies reached approx. 30% DM during summer but less than 20% DM in winter for each filtration layer and sludge. High removal efficiencies, with an average of 96%, 92% and 89% for SS, COD and TKN respectively, were achieved with septage whereas they were lower for the mixture of aerated sludge and septage. The dewaterability of septage and its filtration behaviour were assessed by several parameters (Capillary Suction Time, bound water) which may be some interesting tools for an optimised loading strategy.

Factors that influence cancer patients' anxiety following a medical consultation: impact of a communication skills training programme for physicians.

BACKGROUND: No study has yet assessed the impact of physicians' skills acquisition after a communication skills training programme on the evolution of patients' anxiety following a medical consultation. This study aimed to compare the impact, on patients' anxiety, of a basic communication skills training programme (BT) and the same programme consolidated by consolidation workshops (CW), and to investigate physicians' communication variables associated with patients' anxiety. PATIENTS AND METHODS: Physicians, after attending the BT, were randomly assigned to CW or to a waiting list. The control group was not a non-intervention group. Consultations with a cancer patient were recorded. Patients' anxiety was assessed with the State Trait Anxiety Inventory before and after a consultation. Communication skills were analysed according to the Cancer Research Campaign Workshop Evaluation Manual. RESULTS: No statistically significant change over time and between groups was observed. Mixed-effects modelling showed that a decrease in patients' anxiety was linked with screening questions (P = 0.045), physicians' satisfaction about support given (P = 0.004) and with patients' distress (P < 0.001). An increase in anxiety was linked with breaking bad news (P = 0.050) and with supportive skills (P = 0.013). No impact of the training programme was observed. CONCLUSIONS: This study shows the influence of some communication skills on the evolution of patients' anxiety. Physicians should be aware of these influences.

Effect of reeds and feeding operations on hydraulic behaviour of vertical flow constructed wetlands under hydraulic overloads.

Vertical flow constructed wetlands (VFCWs) have been very successful in France over the last 5 years. The sizing of VFCWs is still roughly based on organic load acceptance with slight clear water intrusion into the sewerage system which is often wrong in the context of small communities. To specify the hydraulic limits would be of great help to Water Authorities in deciding at what point is it preferable to build separate sewers rather than adapt the wastewater treatment plant. The study of the hydraulic limits of reed beds, based on the knowledge of hydrodynamics in unsaturated porous media, shows the ability of the system to accept flow overloads. Measuring different parameters (flow, pollutant removal, infiltration rate (IR), pressure head profiles) in pilot and full-scale studies, we explain the hydraulic behaviour of the filter, and the role of reeds and batch frequency on the IRs. Consequently, new hydraulic limits with accompanying sizing rules and operational recommendations according to the level of deposit on the filter surface are suggested. The study shows the robustness of reed beds systems as designed in France to accept hydraulic overloads. Overloads up to ten times the dry weather flow are possible whilst still complying with the European standards.

How to treat raw sewage with constructed wetlands: an overview of the French systems.

The development of vertical flow constructed wetlands treating raw wastewater in France has proved to be very successful over the last 20 years. In view of this a survey was carried out on more than 80 plants in order to study their performance and correct the design if necessary. This study shows that such systems perform well in terms of respecting the goals of both low level outlet COD and SS and nitrification. Pollutant removal performance in relation to the loads handled and the specific characteristics of the plants were investigated. Nitrification is shown to be the most sensitive process in such systems and performance in relation to sizing is discussed. Such systems, if well designed, can achieve an outlet level of 60 mg L(-1) in COD, 15 mg L(-1) in SS and 8 mg L(-1) in TKN with an area of 2 - 2.5 m2.PE(-1). The sludge deposit on the first stage must be removed after about 10-15 years.

Apatite as an interesting seed to remove phosphorus from wastewater in constructed wetlands.

Intensive use of phosphates has resulted in high P levels in surface waters and therefore eutrophication problems. Over the last decade many studies have revealed the advantage of using specific materials with efficient phosphorus retention capacities. Recent studies state that Ca materials are of particular interest for long-term retention of P, but can induce negative effects. To improve P retention and avoid negative counter-effects we tested the potential of natural apatites. Apatite sorption was evaluated using batch and open reactor experiments. Batch experiments identify sorption mechanisms and the influence of the ionic characteristics of the solution; open reactor experiments evaluate sorption capacities in relation to the ionic composition of the solution and biomass development. In parallel, observation of the material by electron microscopy was used to give more precision information about the mechanisms involved. This work reveals the strong chemical affinity between apatites and phosphorus. Compared to other calcareous materials apatite is better able to maintain low outlet P levels. After more than 550 days feeding, sorption was still present and low P outlet levels were still being obtained when sufficient contact time and calcium content in the solution were ensured. This work demonstrates the advantages of using apatites for phosphorus removal in constructed wetlands. The behaviour of apatite in phosphorus retention is explained and its suitability for use in such extensive systems defined.

Phosphorus retention in subsurface constructed wetlands: investigations focused on calcareous materials and their chemical reactions.

Phosphorus removal from wastewater has been of growing interest for some decades to avoid eutrophication in surface water. In subsurface constructed wetlands precipitation and adsorption are the main mechanisms responsible for P uptake. Two media (calcite and recycled crushed concrete (RCC)) were examined in batch and continuous systems. Batch experiments show attractive sorption capacities, however experiments carried out in open reactors pointed out some limitation in retention capacities and effluent quality. RCC is sensitive to a strong dissolution leading to a quick phosphorus precipitation but induces high conductivity and pH values in the treated water. Calcite efficiency depends on the carbonate equilibrium of the solution. Microscopic observations of the calcite surface show crystal growth of phosphorus precipitate. Crystallisation seems to be the main P uptake once a material's surface is covered.

Use of recycling through medium size granular filters to treat small food processing industry effluents.

Currently there are no suitable wastewater treatment systems for effluents from small food processing industries (dairy, cheese, wine production). Such raw sewages are characterized by high organic matter concentrations (about 10 g COD L-1) and relatively low daily volumes (about 2 m3). An adaptation of attached-growth cultures on fine media processes, known to be easy and inexpensive to use, could fit both the technical and economical context of those industries. Coarser filter particle size distributions than those normally used allow a better aeration and reduce clogging risk. The transit time of the effluent through the porous filter materials is shortened and requires recycling to increase the contact time between the biomass and the substrate. A pilot plant was built to compare the efficiency of two kinds of filter materials, gravel (2-5 mm) and pozzolana (3-7 mm). Two measurement campaigns were undertaken on a full-scale unit dealing with cheese dairy effluents. Both pilot-scale and full-scale plants show high COD removal rates (> 95%). Pilot-scale experiments show that accumulation of organic matter leads to the clogging of the recycling filter. To prevent early clogging, a better definition of feeding cycles is needed.

Modelling of a recirculating granular medium filter's processes.

The effluents of French small farm factories will soon be submitted to regulation. Only a few treatment techniques are available to deal with these kind of effluent (high concentration and small daily volumes). To allow the treatment, in the particular economic context of small food processing industries, Cemagref is trying to adapt a treatment based on attached growth cultures on fine media, a system known to be easy to operate and relatively inexpensive. A model, based on four sub-models (hydrodynamic characteristics, oxygen transport, solute transport in the mobile and immobile phases and bacterial evolution) describes this process. Based on wastewater concentration, hydraulic load, applied organic loads, feeding/rest cycles and recycling phases number, this model predicts: eliminated organic loads and the discharge concentration as a function of time, oxygen and biomass contents as a function of time and depth. The determination of the model's parameters is based on a comparison between simulations and performances achieved on experimental columns. This model would be helpful in sizing full-scale filters treating different types of agro-food wastewater. The aim of this article is to present the model's structure, to give all parameter values and to compare the simulations with the results obtained on pilot and full scale plants.

Enhanced activation of B cells in a granulocyte colony-stimulating factor-mobilized peripheral blood stem cell graft.

In a randomized study that compared human leucocyte antigen-identical allogeneic granulocyte colony-stimulating factor (G-CSF)-mobilized peripheral blood stem cell (PBSC) versus bone marrow (BM) transplantation, the expression of activation markers, CD23, CD25 and CD45RO by B cells, was compared in blood before and after G-CSF mobilization and in PBSC versus BM grafts. The fractions of CD23+ and CD25+ B cells were higher in PBSC than in BM grafts. Moreover, we observed a G-CSF-induced increase in B-cell fractions in blood as well as in PBSC grafts when compared with BM grafts. Such an enhanced B-cell activation could contribute to the accelerated kinetics of immuno-haematological reconstitution, the occurrence of acute haemolysis in the ABO minor incompatibility setting, as well as the increased incidence of chronic graft-versus-host disease observed after PBSC transplantation.

Choice of the sand for sand filters used for secondary treatment of wastewater.

In a range from 100 to about 1,000 People Equivalent (PE), Secondary Wastewater Sand Filters (SWSF) are used by a lot of rural communities in France. A series of case studies however point out that several criteria concerning global and detailed design and implementation of these systems have to be approached scientifically, in order to obtain the expected results on a long-term basis. The choice of the sand constituting the infiltration bed, core of the biological reactor, is of course one of the key elements and is the main subject of this article. It must have a sufficient initial permeability in order to ensure an adapted infiltration speed, after colonisation by the purifying biomass. The d10 fines content and degree of uniformity mainly control this permeability. The quarry or the aggregate extractor, who masters his production this way, usually gives these elements, based on granulometric analysis. However the adjustment of an infiltration test with clear water is essential to check on site the conformity of the deliveries.