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The International Commissions on Radiation Units and Measurements (ICRU) and on Radiological Protection (ICRP) have published a joint report, as ICRU Report 95, recommending new operational quantities for use in radiological protection. The new quantities have been devised to address known problems with the existing ones, including the need to cover a wider range of radiation types and energies, for example arising from the increasing use of proton therapy in clinical procedures. Also related to changing practices is the increased importance of doses at diagnostic x-ray energies below about 80 keV, where the more frequent use of interventional procedures renders less acceptable the over-estimation given by the existing quantities. The new operational quantities are conceptually different from the existing ones, being defined using the same anthropomorphic voxel phantoms as are used to derive the protection quantities. ICRP have carried out a consultation process and ICRU have revised the report in the light of comments received. As part of its strategic research agenda, EURADOS seeks to contribute to the development and understanding of fundamental dose concepts, such as the topic of operational quantities. Accordingly, we have carried out a project to evaluate the impact of the proposed quantities and to make recommendations for their application. The task group included experts drawn from across the various EURADOS working groups. This report analyses the differences between the new and existing quantities before going on to examine the impact and application in the areas of: radiation protection practice, dosemeter and instrument design, calibration and reference fields, European and national regulation, and current published standards. The new quantities will achieve the benefits of wider radiation type and energy coverage, and of improving representativeness in the diagnostic/ interventional photon energy range. The biggest negative impact will be in the area of dosemeter and instrument design. Here, the changes needed to achieve good responses to the new operational quantities will range from simple re-calibration to radical re-design; and some types of dosemeter may become obsolete. Significant investments are therefore required to achieve the aforementioned benefits. We support the recommendation that the introduction of the new quantities should be phased over tens of years. Not only will this provide time for the costs and benefits to be fully assessed and the necessary research to be carried out, it will also allow for consideration of the parallel development of the planned new recommendations from ICRP.

International audience; Purpose To investigate the optimal use of XR-RV3 GafChromic® films to assess patient skin dose in interventional radiology while addressing the means to reduce uncertainties in dose assessment. Methods XR-Type R GafChromic films have been shown to represent the most efficient and suitable solution to determine patient skin dose in interventional procedures. As film dosimetry can be associated with high uncertainty, this paper presents the EURADOS WG 12 initiative to carry out a comprehensive study of film characteristics with a multisite approach. The considered sources of uncertainties include scanner, film, and fitting-related errors. The work focused on studying film behavior with clinical high-dose-rate pulsed beams (previously unavailable in the literature) together with reference standard laboratory beams. Results First, the performance analysis of six different scanner models has shown that scan uniformity perpendicular to the lamp motion axis and that long term stability are the main sources of scanner-related uncertainties. These could induce errors of up to 7% on the film readings unless regularly checked and corrected. Typically, scan uniformity correction matrices and reading normalization to the scanner-specific and daily background reading should be done. In addition, the analysis on multiple film batches has shown that XR-RV3 films have generally good uniformity within one batch (

Skin dose measurement in interventional procedures using XR-RV3 gafchromics can be associated with huge uncertainties due to film properties and performance in clinical conditions. EURADOS WG-12 focused on characterizing these films in standard laboratory and in clinical conditions while addressing the means to reduce uncertainties.

The European Radiation Dosimetry Group, EURADOS is a network of scientists specialized in the field of dosimetry. One of the main topics of EURADOS working group 12 (WG 12) is dosimetry of medical staff, in particular eye lens dosimetry. There is an increased interest amongst the scientific community in this topic for occupationally exposed medical workers due to the new eye lens dose limit and there are many open questions and topics which need to be addressed within this field. An overview of the main tasks undertaken by the working group is presented: a literature review on eye lens dose data and on available procedures for estimating or measuring eye lens doses, the distribution of a questionnaire to European hospitals to collect feedback about the current status of eye lens monitoring in hospitals and the organization of an intercomparison between European individual dosimetry services to verify the performance of available eye lens dosemeters.

Monte Carlo calculations were used to investigate the efficiency of radiation protection equipment in reducing eye and whole body doses during fluoroscopically guided interventional procedures. Eye lens doses were determined considering different models of eyewear with various shapes, sizes and lead thickness. The origin of scattered radiation reaching the eyes was also assessed to explain the variation in the protection efficiency of the different eyewear models with exposure conditions. The work also investigates the variation of eye and whole body doses with ceiling-suspended shields of various shapes and positioning. For all simulations, a broad spectrum of configurations typical for most interventional procedures was considered. Calculations showed that ‘wrap around’ glasses are the most efficient eyewear models reducing, on average, the dose by 74% and 21% for the left and right eyes respectively. The air gap between the glasses and the eyes was found to be the primary source of scattered radiation reaching the eyes. The ceiling-suspended screens were more efficient when positioned close to the patient’s skin and to the x-ray field. With the use of such shields, the H-p(10) values recorded at the collar, chest and waist level and the H-p(3) values for both eyes were reduced on average by 47%, 37%, 20% and 56% respectively. Finally, simulations proved that beam quality and lead thickness have little influence on eye dose while beam projection, the position and head orientation of the operator as well as the distance between the image detector and the patient are key parameters affecting eye and whole body doses.