No abstract

A detailed study of radiation doses received by 168 patients who underwent coronary angiography (CAG) and 102 patients who underwent percutaneous transluminal coronary angioplasty (PTCA) in two Greek hospitals is presented. Radiation dose was measured in terms of dose-area product (DAP). The contribution of fluoroscopy and cineradiography to the total DAP was examined separately for each radiological projection used in both procedures. Effective dose and doses to various organs were estimated with the help of the ODS-60 software. Total DAP was found to correlate linearly to fluoroscopy time and cine film length. Mean DAP values were found to be 80.8 +/- 28.0 Gy cm2 for CAG and 86.2 +/- 65.6 Gy cm2 for PTCAs, whereas the estimated mean values of effective dose were 20.9 +/- 7.5 and 23.2 +/- 18.1 mSv respectively. DAP to effective dose conversion coefficients were estimated to be 0.26 mSv/Gy cm2 for CAG and 0.27 mSv/Gy cm2 for PTCAs.

CT has become the major source of population exposure to diagnostic X-rays. CT dose index (CTDI) and dose-length product (DLP) have been proposed as the appropriate dose quantities for the establishment of diagnostic reference levels for optimizing patient exposure. Dose measurements on 27 CT scanners in Northern Greece involving six routine CT examinations have been performed in order to compare their performance with the currently proposed European reference dose values and to produce a preliminary set of data for the establishment of local diagnostic reference levels. All measurements were performed using a pencil shaped ionization chamber introduced into polymethyl methacrylate cylindrical head and body phantoms. The results revealed significant discrepancies in dose values among the CT scanners, which can be mainly attributed to variations in the examination protocols and the different kinds of scanners. Significant overdosing compared with the European reference levels has not been observed, with the exception of the routine head examination, where 47% of the scanners exceeded the corresponding CTDI(w) value. CT scans in the trunk region result in the higher effective doses, which can reach estimated maximal values of the order of 15 mSv.

Significant changes in the past year have taken place in the world of work that are bringing new challenges with regard to employee safety and health. These changes have led to emerging psychosocial risks (PSRs) at work. The risks are primarily linked to how work is designed, organized, and managed, and to the economic and social frame of work. These factors have increased the level of work-related stress and can lead to serious deterioration in mental and physical health. In tackling PSRs, the European labor inspectorates can have an important role by enforcing preventive and/or corrective interventions in the content and context of work. However, to improve working conditions, unilateral interventions in the context and content of work are insufficient and require adopting a common strategy to tackle PSRs, based on a holistic approach. The implementation of a common strategy by the European Labor Inspectorate for tackling PSRs is restricted by the lack of a common legislative frame with regard to PSR evaluation and management, the different levels of labor inspectors' training, and the different levels of employees' and employers' health and safety culture.

The investigation of the clinical efficacy and effectiveness of Intensity Modulated Radiotherapy (IMRT) using Multileaf Collimators (MLC) and Helical Tomotherapy (HT) has been an issue of increasing interest over the past few years. In order to assess the suitability of a treatment plan, dosimetric criteria such as dose-volume histograms (DVH), maximum, minimum, mean, and standard deviation of the dose distribution are typically used. Nevertheless, the radiobiological parameters of the different tumors and normal tissues are often not taken into account. The use of the biologically effective uniform dose (D = ) together with the complication-free tumor control probability (P + ) were applied to evaluate the two radia- The applied plan evaluation method shows that in the brain cancer, the HT treatment gives slightly better results than the MLC-based IMRT in terms of optimum expected clinical outcome (P + of 66.1% and 63.5% for a D = to the PTV of 63.0 Gy and 62.0 Gy, respectively). In the cranio-spinal axis cancer, the HT plan is significantly better compared to the MLC-based IMRT plan over the clinically useful dose prescription range (P + of 84.1% and 28.3% for a D = to the PTV of 50.6 Gy and 44.0 Gy, respectively). If a higher than 5% risk for complications could be allowed, the complication-free tumor control could be increased by almost 30% compared to the initial dose prescription.