Dosimetric Comparison Between Helical Tomotherapy and Volumetric Modulated Arc Therapy in Patients With Malignant Pleural Mesothelioma.

AIMS: To carry out a dosimetric comparison and constraints feasibility proof of adjuvant radiotherapy through helical tomotherapy or volumetric modulated arc therapy (VMAT) for malignant pleural mesothelioma patients after pleurectomy/decortication. MATERIALS AND METHODS: Retrospective calculations were carried out on previously acquired simulations. A whole-pleura volume with 50.4 Gy in 28 fractions was prescribed, simulating a no residual tumour situation. Calculations were carried out using an anisotropic analytical algorithm with a 2.0 mm grid. Beam-on time, planning target volume (PTV) coverage, homogeneity index and organ at risk exposure were compared. RESULTS: Sixteen patient plans were calculated per device. Constraints were met overall by both modalities. For helical tomotherapy and VMAT plans, median beam-on times were 13.8 (11.6-16.1) min and 6.4 (6.1-7.0) min; P = 0.006. The median left-sided radiotherapy PTV D98 were 48.1 (48.0-48.8) Gy and 47.6 (46.5-48.3) Gy; P = 0.023. No significant difference for right-sided radiotherapy was found. PTV D2 for left-sided radiotherapy was higher with VMAT (P = 0.014). For right-sided radiotherapy, helical tomotherapy showed higher doses (P = 0.039). No homogeneity index differences for left-sided radiotherapy (P = 1.00) and right-sided radiotherapy (P = 0.598) were seen. Significant organ at risk exposure differences were found on left-sided radiotherapy whole-lung V20, as well as D50 (both P = 0.008). Higher contralateral lung and ipsilateral kidney exposures were found with VMAT plans for both treatment sides. CONCLUSION: Adjuvant radiotherapy after pleurectomy/decortication in malignant pleural mesothelioma patients, with a VMAT- or helical tomotherapy-based platform, is dosimetrically feasible. Lung sparing was mostly improved with helical tomotherapy. Technique selection must be carried out according to availability and clinical criteria.

[Gaucher's disease and imiglucerase in 2009/2010: what leads to a suddenly enforced prioritisation?]. / M. Gaucher und Imiglucerase 2009/2010: Was leitet eine plötzlich erzwungene Priorisierung?

Gaucher's disease is, when left untreated, a progressive and in some subsets even life-threatening lysosomal storage disease. It is caused by a genetically linked deficit of acid beta-glucocerebrosidase. The enzyme can be replaced by Cerezyme(®)/imiglucerase produced by Genzyme Corp. The therapy has the potential to induce remis-sion and normalise the patient's life. In June 2009 Genzyme had to announce a viral contamination of its bioreactors which led to a sudden stop of the entire production of imiglucerase. Subsequently only 50-20% of the former supply could be provided worldwide. The situation was not normalised until the beginning of the year 2011. Due to this unexpected shortage the relevant actors had to clarify quickly and unprepared which patient groups to prioritise and whom to supply with what quantities of imiglucerase. The shortly enforced prioritisation and rationing provide an opportunity to describe and analyse the spontaneously choosen prioritisation criteria and reveal value preferences shared by clinicians, patients, patient representatives, and company representatives. To reconstruct the chain of events and reactions and the revealed criteria and value preferences partly standardised interviews with representatives of the relevant stakeholder groups were conducted. Very clearly, the actors spontaneously chose to follow a medical need and a social solidarity principle.

[Criteria for medical prioritisation: results from a regional survey and methodological reflections]. / Kriterien für die Priorisierung medizinischer Leistungen im Licht eines regionalen Surveys--Ergebnisse und methodologische Fragen.

AIMS: In Germany, in contrast to many foreign countries, scientists and medical professionals have been discussing prioritisation in medicine almost without consulting German citizens. We address the question of what questionnaire surveys can contribute to the understanding of citizens' attitudes towards prioritisation - with a focus on some difficulties and challenges of the method. METHOD: We conducted a postal survey with a random sample of 3 000 residents of the City of Lübeck (age ≥18). Respondents were asked to appraise different substantial and procedural criteria for prioritisation in medicine. In addition to descriptive statistical analyses, logistical regression models were performed to identify potential explanatory variables for the appraisal of prioritisation criteria. RESULTS: The response rate was 45.6% (N=1 363). Some prioritisation criteria are accepted by the majority: severity of disease, effectiveness of an intervention and a firm evidence base. Other criteria were appraised controversially: personal life-style, responsibility for family members and general prioritisation of children. A patient's responsibility in society and age as well as an intervention's cost-benefit ratio were generally rejected. The results of logistic regression analyses showed some significant but minor effects of demographic and health-related variables. The citizens in our study want decision-making procedures in health care to be transparent and equally applied to all patients. According to the survey respondents decisions about the catalogue of services of Germany's statutory health insurance should mainly be made by doctors. The statutory health insurance as well as patients and scientists also should take part in the decision-making procedure. DISCUSSION: Comparing our results to those of a national interview survey reveals some relevant differences: The respondents' assessment of some substantial criteria seems to vary according to the contextualisation and wording of the items. We found less difference - but still some inconsistent results - in the participants' appraisal of potential decision-makers in health care. To our surprise, the logistic regression models including standard demographic and health-related variables account for only a small proportion of the variance of all dependent variables. CONCLUSION: Our discussion emphasises some difficulties and challenges of questionnaire surveys on prioritisation criteria - reflecting on the state of the German debate on prioritisation. There has been hardly any public discussion on this issue prior to our survey in autumn 2009. It is thus unlikely that people have been able to state well-informed preferences. Instead they seem to have followed some kind of "social reflexes" depending on the context and wording of each item. Subsequent studies on preferences and priorities should (i) more closely assess the understanding of each item in advance and (ii) adapt the aims of their study and its methodology to the actual stage of the public discourse on the topic in question.

Time-resolved laser fluorescence spectroscopy and extended X-ray absorption spectroscopy investigations of the N3- complexation of Eu(III), Cm(III), and Am(III) in an ionic liquid: differences and similarities.

The complexation of the lanthanide Eu(III) and the actinides Cm(III) and Am(III) by N3- was investigated by application of time-resolved laser fluorescence spectroscopy (TRLFS) and X-ray absorption spectroscopy (XAFS) in the ionic liquid solution of C4mimTf2N (1-butyl-3-methylimidazolium-bis(trifluoromethylsulfonyl)imide). TRLFS measurements show that the interaction of azide with Eu(CF3SO3)3 and Eu(ClO4)3 results in both dynamic luminescence quenching by collisional encounters of N3- with Eu(III) and static luminescence quenching by inner-sphere complexation of Eu(III) by N3-. Hereby, the complexation of Eu-triflate by azide starts at a lower N3- concentration as compared to the perchlorate salt. The authors ascribe this phenomenon to a stronger bonding of ClO4- toward the metal ion than triflate, as well as to a stronger electrostatic repulsion of N3- by the perchlorate ligand. In both actinide samples (Cm(ClO4)3, Am(ClO4)3), the complexation with azide exhibits a clear kinetic hindrance. Nevertheless, mixed actinide-perchlorate-azide complexes are formed after several days in C4mimTf2N. The different reaction kinetics for the Ln- and An-complexation by azide may provide the opportunity for an effective separation of lanthanides from actinides in the nuclear fuel cycle by the use of N-based extractants in ionic liquid solution.

Immobilization of trivalent actinides by sorption onto quartz and incorporation into siliceous bulk: investigations by TRLFS.

The adsorption of Cm(III) on quartz is studied by time resolved laser fluorescence spectroscopy (TRLFS) in the pH range from 3.75 to 9.45. The raw spectra are deconvoluted into three single components. The first one has a peak maximum at 593.8 nm and can be attributed to the Cm(III) aquo ion with an emission lifetime of 68+/-3 micros. The second one corresponds to an adsorbed species and has a peak maximum at 601.4 nm and an emission lifetime of 123+/-10 micros. The peak maximum of the third component is shifted to higher wavelength (603.6 nm) while the lifetime remains constant. Additionally, the adsorption of Am(III) on quartz is investigated in batch experiments. Based on the spectroscopic data a sorption mechanism is suggested. In addition, the obtained Am uptake data and the Cm-TRLFS data are modeled simultaneously using a single site Basic Stern model in combination with the charge distribution concept of Pauling. The finally suggested model consists of two bidentate surface complexes where the second one is the product of hydrolysis of the first sorption species. In a separate set of experiments the influence of silicic acid at different concentrations on the Cm(III) speciation in a quartz system is investigated by TRLFS. In suspension silicic acid at low concentration (3.5x10(-4) mol/L) has no influence on the Cm(III) speciation. At high concentration (3.5x10(-2) mol/L) the Cm(III) speciation is definitely influenced. The results at higher concentration indicate the formation of Cm(III)/silicic acid complexes and the incorporation of Cm(III) into siliceous bulk. This is confirmed by measurements at a quartz single crystal surface. Moreover, these measurements indicate the formation of quartz/Cm(III)/silicic acid ternary complexes at the mineral surface.

Survey of smoking knowledge, attitudes and practice in school children in Honduras.

OBJECTIVE: The aim of this study was to survey Honduran pre-adolescent knowledge, perceptions and experience regarding smoking. METHODS: A 12-item survey was administered in the classroom to fifth and sixth grade students. The main outcome measures were a description of demographic factors, personal smoking experience, knowledge of health risks, attitudes about tobacco use and perceived sources of information. RESULTS: A total of 225 students were surveyed. The majority were aware that smoking is bad for health, and most reported never having smoked. Most viewed smoking as ugly. Friends and family were selected as the major source of information. CONCLUSIONS: School children in this area of Honduras are aware of the health risks of smoking and view smoking as unattractive.

Finding meaning in reporting requirements. Provider sampling and survey length.

Meeting compliance requirements to report information such as provider satisfaction typically inspires groans, followed by hasty actions by those who must collect and supply the information. Reports often reflect this lack of interest as findings are rarely defended as representative. Our medical group employed statistical methodology to make this process meaningful while also keeping it fairly simple and without incurring added costs. By establishing our provider satisfaction survey as a scientifically based endeavor, we improved the likelihood the provider would actively and honestly participate, and report findings with confidence.

Pilot study of a rating instrument for medical education Web sites.

Standardized evaluation criteria would be useful for sorting through the huge volume of medical educational information now available on the Internet. The authors developed and pilot-tested a simple rating instrument. Using this instrument, students identified preferred Web sites and indicated that speed was particularly important in their assessments.

Cross cultural communication to help physician assistants provide unbiased health care.

Teaching cross cultural communication typically involves instruction in differences between groups. As part of this course in cross cultural communication, six specific underserved population groups are introduced to students as a cultural experience. Additionally, instruction is provided to sensitize students to their personal biases and prejudices through videotaped mock interviews. The combination of instruction and experience forms a paradigm for teaching cross cultural communication in a way that has personal and immediate impact on faculty members and students. The model, "Differences + Discomforts = Discoveries," inhibits factionalizing and promotes depth of knowledge about underserved groups as well as personal awareness of prejudicial feelings. As a result, students learn techniques to provide unbiased health care to these, and other, populations.

Food safety assessment reflecting cultural changes, novel hazards, and human values.

An analysis of the cultural values of modern society suggests the desire for an abundant nutritious food supply in all seasons, but at the same time causes increasing concern about the safety of food ingredients. The procedures that give benefits also raise questions of safety. The wide range of societal values cover a spectrum but can be ranked according to their importance. These values will exact a price in the form of some risk. It is possible to balance hazards against cultural values, and benefits are an integral part of the calculus of safety assessment. However, every effort should be made to match the highest benefit with the lowest risk and these considerations have a bearing upon regulatory agencies as they seek to arrive at food safety decisions. A consideration of cultural and human values shifts the regulator's focus from risk only to a quite different task of balancing risks vs benefits in deciding on substances in foods.