N. A. Alomairy et al.: Radioprotection 2026, 61( 2), 132 – 139 133
Recent reports on mean glandular dose( MGD) in mammography from some countries have revealed scattered values. In Sudan, MGD was 1.54 mGy( CC) and 1.58 mGy( MLO)( Abdallah et al., 2021); in Greece, 1.2 mGy( CC) and 1.5 mGy( MLO)( Tsapaki et al., 2008); and in Malaysia, 1.54 mGy( CC) and 1.82 mGy( MLO)( Jamal et al., 2003). Factors affecting MGD include CBT, beam quality, and projection angle, with no correlation to ethnicity, BMI, or age. These findings emphasize the requirement for rigorous quality control in mammography to achieve optimum image quality at the lowest possible radiation doses.
The aim of this study is to evaluate MGD in mammography, identify dose optimization factors, and compare CC and MLO views with international to ensure compliance with radiation protection guidelines. The goal is to improve Saudi Arabian mammography techniques in accordance with the ALARA( As Low As Reasonably Achievable) principle and breast cancer screening practice to ensure better patient safety and outcomes.
2 Materials and methods
2.1 Study design and setting
In this study, the mammography system at a university hospital was utilized. This study was a retrospective crosssectional analysis conducted on a sample of 325 patients, all of whom were evaluated after machine installation. The sample size was chosen based on the machine’ s usage history and to facilitate comparisons with previous national and international studies. The patients were scanned using two main views, CC and MLO projections. The data was collected using the Picture Archiving Communication System( PACS) over the period of January 2022 to October 2024. The study sample was comprised of female patients aged 40 yr and older who were undergoing routine screening or diagnostic mammography. Patients with a history of breast surgeries that could affect dose estimation, those who had previously had breast radiation therapy, pregnant or breastfeeding women, and images with missing information were excluded.
2.2 Ethical considerations
To ensure transparency, all ethical considerations were adhered to, including obtaining approval from the committee of Standing Committee Publication and Research Ethics( Reference number: REC-46 / 06 / 1244). In addition, all patient data underwent anonymization to maintain confidentiality and privacy. The study adhered to the principles outlined in the Declaration of Helsinki, thus ensuring that the rights and wellbeing of patients took precedence during the investigative procedure. Because of the retrospective nature of the data collection, the individual patient consent requirement was waived for this study.
2.3 Machine specification
The mammography machine used at the University Hospital is the Fujifilm AMULET Innovality( Model FDR MS-3500). It produces high-resolution images with a minimal dose includes dual-mode tomosynthesis and comfort features. Key output specifications include a maximum tube voltage of 49 kV at 450 mAs( 102 mA), and a maximum current of 200 mA at 35 kV with 90 mAs. The unit also delivers up to 600 mAs at 30 kV with 166 mA. The source-to-image distance( SID) is 65 cm, and the maximum field size is 24 cm 30 cm.
This machine employs a Tungsten( W) target with a Rhodium( Ru) filter. The machine apparatus utilized were subjected to quality control assessments by a specialized local team, with the most recent quality control taking place in February 2024.
2.4 Dosimetric assessment
The Mean Glandular Dose( MGD) is used as the dosimetric measurement in mammography, defined as the mean dose to the glandular tissue of the breast. To gather relevant parameters, a data sheet was used, collecting parameters such as compressed breast thickness( CBT), target and filter material, maximum electrical voltage( kVp), time-current product( mAs), and half-value layer( HVL). Additionally, CBT was estimated using data from the reference tube voltage( kVp), electrical current( mAs), and the target / filter combination. The MGD was calculated indirectly from the entrance surface dose( K) and half-value layer( HVL). The last quality control records indicated that beam quality, measured by the half-value layer( HVL), was 0.5 mm, which was used in the MGD calculations. The conversion coefficients used for this calculation are derived from Monte Carlo simulations of typical breast projections, assuming a 50 % distribution between adipose( fatty) and glandular tissues. In this study, the conversion coefficients provided by Dance et al.( 2009) were employed to extrapolate the MGD. The estimation of the MGD was carried out using an indirect method, which involved inputting specific parameters into a mathematical equation( 1), as specified by Dance( Dance et al., 2000).
MGDðmGyÞ ¼ Kxgxcxs; ð1Þ
where K is the Entrance Surface dose reported in the machine; g is the conversion factor for the 50 % glandular breast based on thickness and HVL( Dance et al., 2000); c is the factor that corrects for differences in compression of a typical breast compared to the 50 % glandular size( Dance et al., 2000); and s = 1.042 is the factor that corrects for differences due to the choice of X-ray spectrum( Dance et al., 2000).
2.5 Statistical analysis
The data was collected and organized in a Microsoft Excel spreadsheet. It underwent statistical analysis, incorporating both descriptive and inferential statistics, using the SPSS software( Version 26, SPSS Inc., Chicago, IL, USA). Pearson’ s correlation testing was performed to assess the relationships between patient age, compressed breast thickness( CBT), exposure parameters, and radiation dose metrics. Multiple linear regression was conducted to identify independent predictors of the mean glandular dose( MGD). The dependent variable was MGD( in mGy) and the independent variables were patient age, compressed breast thickness( CBT in cm),