Establishing new copper filtered radiation qualities in SSDL for general radiography and fluoroscopic applications

It is good practice that diagnostic dosimeters are calibrated in laboratory conditions, prior to their application in quality control. Clinical need-driven design considerations in X-ray sources have led to numerous technological advancements resulting in a noticeable difference between radiation conditions encountered in clinical applications and those established in calibration laboratories. One of the aims of the Joint Research Project 22NRM01 TraMeXi is development of new calibration qualities and testing procedures, that better reflect clinical conditions. The reference radiation conditions defined for general radiography and fluoroscopy are outlined in IEC 61267:2005 [IEC, 2005]. They include the aluminum (Al) filtered RQR radiation quality series and the copper (Cu) filtered RQC radiation quality series. New X-ray generators encountered in hospitals use total filtrations comprised of aluminum and additional copper filtrations of different thicknesses. Typical total filtration of X-ray generators was investigated via a European scale survey. The largest additional copper thickness encountered in clinical practice is the 0.9 mm Cu (found for stationary C-arms). This shows that the RQC Cu filtration does not fully represent clinical conditions. Therefore, new radiation qualities, termed as Clinically relevant and Physical Representative Radiation Qualities (CPRQ), were established in the Vinca Institute of Nuclear Sciences (VINS) and the Greek Atomic Energy Commission (GAEC) by adding 0.9 mm Cu filtration to selected RQR qualities. Bilateral comparison of Half Value Layers and the homogeneity coefficient was performed. The HVL values were also compared with the values generated by the SpekCalc [Poludniowski et al., 2009] software. Calibration of a semiconductor-based X-ray multimeter was performed in these radiation fields and its energy dependence, in terms of dosimeter relative response normalized to RQR5 radiation quality. Performance evaluation was based on the criteria defined in IEC 61674:2024 [IEC, 2024]. Calibration of dosimeters used in these radiation fields would enhance measurement accuracy and reliability, improving quality assurance and patient dose estimates.