Towards National Diagnostic Reference Levels for Mammography in Serbia

The objective of this work is to investigate the possibility to set a national diagnostic reference levels (nDRLs) for diagnostic and screening mammography in Serbia based on local practice and available resources. This study included all types of mammography systems that are currently used in Serbia, namely screen-film mammography (SFM), computed radiography (CR) and full-field digital mammography (FFDM). The nDRLs are provided in terms of mean glandular dose (MGD) for different breast thicknesses simulated by polymethyl methacrylate (PMMA) phantom. For each breast thickness, MGD was calculated for the X-ray tube output, using clinically used exposure parameters. DRLs were chosen as the 75th percentile of MGD distribution for 20-, 40-, 45-, 60- and 70-mm phantom thicknesses. For SFM units proposed nDRL values are 0.7, 2.1, 2.7, 4.6 and 6.8 mGy; for CR units proposed nDRL values are 0.7, 1.8, 2.4, 4.5 and 5.6 mGy; and corresponding values for FFDM units are 0.8, 1.7, 2, 2. and 3.2 mGy for 20-, 40-, 45-, 60- and 70-mm PMMA thickness, respectively.