Significance of the sample determination in assessment of radiological examinations frequencies for population doses due to medical exposures.

The radiological examination frequency, i.e. the number of examinations performed annually, is necessary for estimating the collective effective dose of the population from medical exposures with ionizing radiation. Examination frequency surveys usually collect data from a limited number of radiological facilities participating in the survey. The collected data are then extrapolated to the existing radiological facilities in a country/region. Thus, the number of facilities and the specific facilities to participate, as well as, the extrapolation method used, are significant elements when designing the survey sample and methodology for examinations frequency assessments. This work attempted to simulate the situation when examination frequency data are collected from a limited number of facilities by investigating several "virtual sample" designs and two extrapolation methods. Comparisons between the calculated - by extrapolation - and the actual examination frequency in the country were made, for several scenarios and examination type data sets. The uncertainties were estimated and discussed thoroughly. The findings of this work highlighted the need for appropriate registry of the existing facilities in a country/region, the categorization of facilities considering the medical sector pattern in the country/region, the representativity and homogeneity of the samples used for a survey, as well as, the necessity for quality control of the collected examination frequency data. The results showed that when the aforementioned conditions were fulfilled, the examination frequency could be calculated with reasonable accuracy, based on data collected from a limited number of facilities. The paper also provides suggestions and tips for the collection and analysis of examination frequency data.

Remote virtual regulatory inspections of facilities and practices utilising ionising radiation and MRI installations during the Covid-19 pandemic.

Covid-19 pandemic imposes crucial social distancing rules and restriction measures; therefore, the access to facilities and sites, in order to perform on-site inspections, became difficult or not feasible. Greek Atomic Energy Commission (EEAE) adopted remote virtual inspections (RVIs) of facilities and practices applying ionising radiation and magnetic resonance imaging installations, in order to continue discharging its regulatory duty of inspection, effectively. This study presents the experience gained and lessons learnt from the implementation of the RVIs and explores the RVIs perception by the stakeholders. Moreover, the effectiveness and the capability of RVIs to identify 'findings', is assessed by comparing the on-site and the remote inspections outcomes. The presented study showed that RVIs could not replace the on-site inspections, entirely; however, they could support and contribute to the inspection activities and program, in certain circumstances. RVIs were proven to be a valuable tool for the inspection of procedures, documents and records as well as the design and operational conditions of the facilities. The performance of remote verification tests and measurements, although feasible, was challenging, due to the technical issues needed to be resolved in advance. The comparison between remote and on-site inspections outcomes showed that both inspection options had similar capability to identify 'findings', indicating the validity of the RVIs as an inspection methodology in certain inspection thematic areas. The perception of the RVIs was positive and the added value and usefulness was acknowledged by the inspected facilities' personnel and the EEAE's inspectors, although the latter mainly considered RVIs as complementary and supportive to the on-site inspections.

Prevention of and response to inadvertent exposure of embryo/fetus to ionizing radiation, due to medical exposure of the mother. The Greek regulatory authority initiatives.

Embryo/fetus (E/F) irradiation as a result of medical exposure of the mother should be avoided, unless there are strong clinical indications. Medical practitioners are assigned the primary task and obligation of ensuring overall patient protection and safety in the prescription of and during the delivery of medical exposure. In cases of unintended exposure of embryo/fetus (E/F), the risk analysis and communication is conducted by or under the supervision of medical physicists at local level. National competent authorities can contribute to the prevention, risk analysis and communication of inadvertent E/F exposure to ionizing radiation by recording, analyzing and disseminating the relevant information. Since 2001, Greek Atomic Energy Commission has established a committee with the mandate to provide advice, to keep records, to analyze and disseminate the experience gained in cases of unintended E/F exposure. During the period 2001-2011, the committee was consulted by 269 pregnant women undergone medical exposures. The conclusions from the relevant data analysis, as well as the experience gained are herein presented and discussed.