National Diagnostic Reference Levels for Standard Descending Thoracic Endovascular Aortic Repair and Optimisation Strategies.

OBJECTIVE: The International Commission on Radiological Protection has highlighted the large number of medical specialties that use fluoroscopy outside diagnostic imaging departments without radiation protection programmes for patients and staff. Vascular surgery is one of these specialties. Thoracic endovascular aortic repair (TEVAR) is a complicated procedure requiring radiation protection guidance and optimisation. The recent EU Basic Safety Standards Directive requires the use and periodic updating of diagnostic reference levels (DRLs) for interventional procedures. The aim of this study was to determine doses for patients undergoing TEVAR with mobile Xray systems and hybrid rooms (fixed Xray systems) to obtain national DRLs and to suggest optimisation actions. METHODS: This was a retrospective cross sectional study. The Spanish Chapter of Endovascular Surgery conducted a national survey in 11 autonomous communities representing around 77.6% of the Spanish population (47.33 million inhabitants). A total of 266 TEVAR procedures from 17 Spanish centres were analysed, of which 53.0% were performed in hybrid operating rooms. National DRLs were obtained and defined as the third quartile of the median values from the different participating centres. RESULTS: The proposed national DRLs are: for kerma area product (KAP), 113.81 Gy·cm2 for mobile Xray systems and 282.59 Gy·cm2 for hybrid rooms; and for cumulative air kerma (CAK) at the patient entry reference point, 228.38 mGy for mobile systems and 910.64 mGy for hybrid rooms. CONCLUSION: Based on the requirement to know radiation doses for standard endovascular procedures, this study of TEVARs demonstrated that there is an increased factor of 2.48 in DRLs for KAP when the procedure is performed in a hybrid room compared with mobile C-arm systems, and an increased factor of 3.98 in DRLs for CAK when the procedure is performed with hybrid equipment. These results will help to optimise strategies to reduce radiation doses during TEVAR procedures.

Recommendations for validation testing of home pregnancy tests (HPTs) in Europe.

Home pregnancy tests (HPTs) available in Europe include accuracy and other performance claims listed on their packaging. Due to the lack of guidance on the standardisation of such products, it is often difficult to replicate these claims when tested on a clinical sample, whether in a laboratory setting or by lay users. The In Vitro Diagnostic Regulation is a set of requirements that mandate comprehensive validation data on human pregnancy tests and other in vitro devices. It is due to replace the current European Directive (98/79/EC) and fully implemented in Europe by 2022. In June 2019, a panel of seven experts convened to discuss the validation studies required to provide the information needed to meet the new regulation for HPTs in Europe and proposed 15 recommendations for best practice. Defining best practice at all stages of validation of these important tests may ensure that tests marketed in Europe are fit for purpose, enabling lay users to be confident of the high quality of the HPT results they obtain. The panelists believe that the recommendations proposed here for the validation of HPTs may constructively contribute to improved standardisation of validation procedures in Europe.

National Diagnostic Reference Levels for Endovascular Aneurysm Repair and Optimisation Strategies.

OBJECTIVE: The International Commission on Radiological Protection (ICRP) has highlighted the large number of medical specialties using fluoroscopy outside imaging departments without programmes of radiation protection (RP) for patients and staff. Vascular surgery is one of these specialties and endovascular aneurysm repair (EVAR) is one of the most challenging procedures requiring RP guidance and optimisation actions. The recent European Directive on Basic Safety Standards requires the use and regular update of diagnostic reference levels (DRL) for interventional procedures. The objective of the study was to know the doses of patients undergoing EVAR with mobile Xray systems and with hybrid rooms (fixed Xray systems), to obtain national DRLs and suggest optimisation actions. METHODS: The Spanish Chapter of Endovascular Surgery launched a national survey that involved hospitals for 10 autonomous communities representing the 77% of the Spanish population (46.7 million inhabitants). Patient dose values from mobile Xray systems were available from nine hospitals (sample of 165 EVAR procedures) and data from hybrid rooms, from seven hospitals, with dosimetric data from 123 procedures. The initial national DRLs have been obtained, as the third quartile of the median values from the different centres involved in the survey. RESULTS: The proposed national DRLs are 278 Gy cm2 for hybrid rooms and 87 Gy cm2 for mobile Xray systems, and for cumulative air kerma (cumulative AK) at the patient entrance reference point, 1403 mGy for hybrid rooms, and 292 mGy for mobile systems. CONCLUSION: An audit of patient doses for EVAR procedures to identify optimised imaging protocol strategies is needed. It is also appropriate to evaluate the diagnostic information required for EVAR procedures. The increase by a factor of 3.2 (for kerma area product) and 4.8 (for cumulative AK) in the DRLs needs to be justified when the procedures are performed in the hybrid rooms rather than with mobile Xray systems.

The new lens dose limit: implication for occupational radiation protection.

AIM AND OBJECTIVES: The aim of this article was to explore the implications of the new Euratom dose limit for occupational radiation protection in the context of medical occupational radiation exposures. The European Directive 2013/59/Euratom takes into account the new recommendations on reduction in the dose limit for the lens of the eye for planned occupational exposures released in 2012 by the International Commission on Radiological Protection (ICRP 118). MATERIALS AND METHODS: Different dose-monitoring procedures and devices were considered. Occupational eye lens doses reported by previous studies were analyzed, mainly considering workers involved in interventional procedures with X-rays. The current status of eye lens radiation protection and the main methods for dose reduction were investigated. RESULTS: The analysis showed that the workers, potentially exceeding the new limit, are clinical staff performing interventional procedures with a relatively high X-ray dose. Regarding radiological protection issues, the considered literature reports that the proper use of personal protective equipment may reduce the eye lens absorbed dose. CONCLUSION: The evaluation of the occupational eye lens dose is essential to establish which method of personal dose monitoring should be preferred. Furthermore, education and training about the right use of personal protective equipment are important for medical staff working with ionizing radiation.

Practical recommendations for the application of DE 59/2013.

The changes introduced with Council Directive 2013/59/Euratom will require European Member States adapt their regulations, procedures and equipment to the new high standards of radiation safety. These new requirements will have an impact, in particular, on the radiology community (including medical physics experts) and on industry. Relevant changes include new definitions, a new dose limit for the eye lens, non-medical imaging exposures, procedures in asymptomatic individuals, the use and regular review of diagnostic reference levels (including interventional procedures), dosimetric information in imaging systems and its transfer to the examination report, new requirements on responsibilities, the registry and analysis of accidental or unintended exposure and population dose evaluation (based on age and gender distribution). Furthermore, the Directive emphasises the need for justification of medical exposure (including asymptomatic individuals), introduces requirements concerning patient information and strengthens those for recording and reporting doses from radiological procedures, the use of diagnostic reference levels, the availability of dose-indicating devices and the improved role and support of the medical physics experts in imaging.

French academic's views on financial compensation of participants.

BACKGROUND: Whether and how participants in biomedical research should receive financial compensation is debated. We wished to explore how this issue was perceived by French professionals, focusing on different conditions of research. MATERIALS AND METHODS: We surveyed referent responders of Clinical Investigation Centres, Research Ethics Committees and hospital administrative departments for clinical research, via referent responders who completed an online questionnaire on behalf of their respective teams. Financial compensation was addressed in terms of general perception, justifications, interpretation of French law, concrete clinical situations and compensation of incurred expenses. Descriptive analyses and correlations were carried out based on scalar responses. RESULTS: The questionnaire was answered by 54/116 (45·6%) centres. The ethical aspects of compensation were viewed differently by Clinical Investigation Centres and Research Ethics Committees, whereas the practical aspects were viewed similarly. Agreement to compensation for patients was lower than for healthy volunteers (74·1 vs. 98·2%). The most frequently cited justifications for compensation apart from the inconveniences of research were the potential risk and the absence of medical benefit. Most of the proposed expenses incurred were to be compensated, but agreement to reimbursement of petrol bills or childcare expense was lower. CONCLUSIONS: Although some of the responses align with previous surveys in other countries, this information may help French professionals to harmonise their practices. We also addressed practical issues which could be studied in other European countries, for professionals and participants. Finally, the reluctance to compensate patients requires further study, taking into account welfare environment and consequences for recruitment.

[Authorization of tissue and blood stem cell preparations for hematopoietic reconstitution: Documentation of clinical and nonclinical data in a central expert report]. / Genehmigungsverfahren für Gewebezubereitungen und Blutstammzellzubereitungen zur hämatopoetischen Rekonstitution: Dokumentation klinischer und nicht klinischer Daten mittels eines Zentralgutachtens.

In order to address the European Directive 2004/23 on human tissues and cells, the authorization obligation for tissue and blood stem cell preparations was introduced (§ 21a AMG) in the year 2007 in the German medicinal products act. Stem cell transplantation for hematopoietic reconstitution has been in use for decades and is well established for the treatment of many malignancies. The manufacture of stem cell preparations varies, but in terms of hematopoietic reconstitution, different products are intended for the same indication. Taking these aspects into account, it was considered inappropriate that every single applicant should provide their own documentation, including an expert report on clinical and nonclinical data. Consequently, the idea came up to create a central expert report, to which all applicants could refer and would include relevant clinical and nonclinical data according to current knowledge. A central expert report was therefore generated, called the "Gemeinsame Stellungnahme der Fachgesellschaften Deutsche Gesellschaft für Transfusionsmedizin und Immunhämatologie (DGTI), Deutsche Gesellschaft für Hämatologie und Onkologie (DGH) und Gesellschaft für Pädiatrische Onkologie und Hämatologie (GPOH)". Applicants are allowed to refer to this central expert report provided their stem cell product is comparable with the cell preparations included in the report. In order to represent current knowledge, the content of the central expert report was already reworked once, but should be updated regularly.

Difficulties in applying numerical simulations to an evaluation of occupational hazards caused by electromagnetic fields.

Due to the various physical mechanisms of interaction between a worker's body and the electromagnetic field at various frequencies, the principles of numerical simulations have been discussed for three areas of worker exposure: to low frequency magnetic field, to low and intermediate frequency electric field and to radiofrequency electromagnetic field. This paper presents the identified difficulties in applying numerical simulations to evaluate physical estimators of direct and indirect effects of exposure to electromagnetic fields at various frequencies. Exposure of workers operating a plastic sealer have been taken as an example scenario of electromagnetic field exposure at the workplace for discussion of those difficulties in applying numerical simulations. The following difficulties in reliable numerical simulations of workers' exposure to the electromagnetic field have been considered: workers' body models (posture, dimensions, shape and grounding conditions), working environment models (objects most influencing electromagnetic field distribution) and an analysis of parameters for which exposure limitations are specified in international guidelines and standards.

Modes of action of three disinfectant active substances: a review.

This review deals with three categories of active substances for disinfectant products, their modes of action (MOA), and how MOA can help predict propensity for resistance in microorganisms. Within the European Union applications for approval of disinfectants of all kinds must be submitted in a few years, and documentation on MOA and resistance must be part of those applications. Peracetic acid is an unspecific, pervasive oxidizer of C-C double bonds and reduced atoms. This MOA would imply poor chance for development of resistance in microorganisms, as borne out by the absence of such reports in the literature. The quaternary ammonium compounds (QAC's) are much more specific in their antimicrobial mechanism. Even very low concentrations cause damage to the cytoplasmic membrane due to perturbation of the bilayers by the molecules' alkyl chains. Development of microbial resistance to QAC's, as well as cross-resistance to antibiotics, are particularly well documented. The polymer PHMB is antimicrobial because it disturbs the cell membrane's bilayer by interacting with it along the surface of the membrane. Resistance to the polymer appears not to develop despite many years of use in many fields. However, PHMB's toxicity to humans upon inhalation dictates great caution when deploying the substance.

Coding of tissue preparations with eurocode in Germany.

SUMMARY: A safe look back of products requires their unique identification. Blood products are encoded in Germany with Eurocode since 1987. EU Directives 2004/23/EC und 2006/86/EC demanded unique identification and safe look back procedure also for tissues and cells. Eurocode IBLS e.V. and the DGTI working parties 'Tissue Preparations' and 'Automation and Data Processing' supplemented the already available Eurocode nomenclature for blood products with further data structures for tissue preparations and deliberated the federal authorities during the EU hearings. In result all EU member states can administer the coding system oneself, but have to take care about the 'key code' structure as defined and the common part at the begin of the ID number of the preparations. Eurocode today offers an EU-conform coding system considering various aspects of blood, tissue and cell preparations in an ISO-standardized form.

High-Dose Fluoroscopically Guided Procedures in Patients: Radiation Management Recommendations for Interventionalists.

The article is part of the series of articles on radiation protection. You can find further articles in the special section of the CVIR issue. In addition to the risks from fluoroscopic-guided interventional procedures of tissue injuries, recent studies have drawn attention to the risk of stochastic effects. Guidelines exist for preprocedural planning and radiation management during the procedure. The concept of a substantial radiation dose level (SRDL) is helpful for patient follow-up for tissue injury. The uncommon nature of tissue injuries requires the interventionalist to be responsible for follow-up of patients who receive substantial radiation doses. Dose management systems for recognizing and avoiding higher patient exposures have been introduced. The European Directive provides a legal framework and requirements for equipment, training, dose monitoring, recording and optimization that are helpful in radiation risk management.

EFOMP policy statement 16: The role and competences of medical physicists and medical physics experts under 2013/59/EURATOM.

On 5 December 2013 the European Council promulgated Directive 2013/59/EURATOM. This Directive is important for Medical Physicists and Medical Physics Experts as it puts the profession on solid foundations and describes it more comprehensively. Much commentary regarding the role and competences has been developed in the context of the European Commission project "European Guidelines on the Medical Physics Expert" published as Radiation Protection Report RP174. The guidelines elaborate on the role and responsibilities under 2013/59/EURATOM in terms of a mission statement and competence profile in the specialty areas of Medical Physics relating to medical radiological services, namely Diagnostic and Interventional Radiology, Radiation Oncology and Nuclear Medicine. The present policy statement summarises the provisions of Directive 2013/59/EURATOM regarding the role and competences, reiterates the results of the European Guidelines on the Medical Physics Expert document relating to role and competences of the profession and provides additional commentary regarding further issues arising following the publication of the RP174 guidelines.

Radiofrequency Exposures of Workers on Low-Power FM Radio Transmitters.

Low-power radio transmitters are one of the most common radio frequency sources and the exposure limit values (ELVs) for occupational exposure may be exceeded close to them. Therefore, a detailed analysis and assessment of occupational exposure in their vicinity is presented in the paper. For 20 different exposure scenarios, electric field strength and specific absorption rate (SAR) values were computed to determine whether the action levels (ALs) and ELVs of the European directive 2013/35/EU are exceeded for different 500 W radio transmitters. The results show that the ALs are very conservative for such exposure situations. Even when the ALs are greatly exceeded, the SAR values are not necessarily above the limit. However, in some situations, the ELVs were also exceeded. The local 10 g averaged value of the SAR can be exceeded if the worker is grounded (in direct contact with the steel structure), while the whole body ELVs can be exceeded for exposures at distances of <1 m from the transmitting dipole array antennas.

Metazachlor traces in the main drinking water reservoir in Luxembourg: a scientific and political discussion.

This discussion is centralized around an incident that took place in the Belgian village Witry the 17th of September 2014. A tractor accident led to the discharge of an aqueous solution of the herbicide metazachlor into the creek Moyémont that further merges into the river Sûre. About 20 km downstream, these waters supply the lake of the Upper-Sûre in Luxembourg, the biggest artificial lake and the main drinking water reservoir in the country. The evolution of the concentration of metazachlor and its metabolite 479M08 was partially tracked down from the river Sûre to the dam situated in the east. At this location, the SEBES drinking water treatment plant has its raw water intake from the lake. After this incident, substantial pollution by the metazachlor breakdown product 479M08 of the lake and of some other groundwater sources in the Grand Duchy was revealed due to a strong monitoring program that was started by the national water authority (AGE). This was for example the case in the SEBES groundwater resource Scheidhof close to Luxembourg City. There is also the reason to assume that contamination by 479M08 existed already in the lake before the incident in Witry, certainly due to agricultural activity. In the second part of this discussion, these perceptions are placed in their appropriate political context. Indeed, the quality of groundwater and drinking water is strongly regulated in the European Union and in Luxembourg. Compound 479M08, for instance, is submitted to a maximum parametric value of 0.1 µg/L in Luxembourg. Several short- and longtime political measures had to be taken to guarantee the wholesomeness of the water from a legal point of view.

Noise reduction in urban LRT networks by combining track based solutions.

The overall objective of the Quiet-Track project is to provide step-changing track based noise mitigation and maintenance schemes for railway rolling noise in LRT (Light Rail Transit) networks. WP 4 in particular focuses on the combination of existing track based solutions to yield a global performance of at least 6dB(A). The validation was carried out using a track section in the network of Athens Metro Line 1 with an existing outside concrete slab track (RHEDA track) where high airborne rolling noise was observed. The procedure for the selection of mitigation measures is based on numerical simulations, combining WRNOISE and IMMI software tools for noise prediction with experimental determination of the required track and vehicle parameters (e.g., rail and wheel roughness). The availability of a detailed rolling noise calculation procedure allows for detailed designing of measures and of ranking individual measures. It achieves this by including the modelling of the wheel/rail source intensity and of the noise propagation with the ability to evaluate the effect of modifications at source level (e.g., grinding, rail dampers, wheel dampers, change in resiliency of wheels and/or rail fixation) and of modifications in the propagation path (absorption at the track base, noise barriers, screening). A relevant combination of existing solutions was selected in the function of the simulation results. Three distinct existing solutions were designed in detail aiming at a high rolling noise attenuation and not affecting the normal operation of the metro system: Action 1: implementation of sound absorbing precast elements (panel type) on the track bed, Action 2: implementation of an absorbing noise barrier with a height of 1.10-1.20m above rail level, and Action 3: installation of rail dampers. The selected solutions were implemented on site and the global performance was measured step by step for comparison with simulations.

The use of isotretinoin in acne.

Systemic isotretinoin remains the most efficacious treatment for severe acne as well as many cases of more moderate disease that are unresponsive to other treatment modalities. The current chapter outlines the mechanisms behind the excellent efficacy, describes how to optimize treatment, reviews the recommended guidelines for monitoring and summarizes adverse effects.