Quality Assurance and Average Glandular dose Measurement in Mammography Units

Assessment of average glandular dose in mammography practice of a teaching hospital in Ghana

Introduction

above the age of 40, women are advised to begin breast examinations and screenings for early detection of breast cancer. The average glandular dose (AGD) provides dosimetric information about the quantity of radiation received by the mammary glands during mammographic exposures. There is, therefore, the need to analyse the radiation dose received by patients presenting for mammography examinations.

Methods

a retrospective cross-sectional design was carried out on the data of 663 participants, conveniently sampled between the months of July 2021 and June 2022. Paired T-test was used to compare imaging parameters for cranio-caudal (CC), medio-lateral (ML), automatic exposure control (AEC), manual exposure control (MEC), and left and right breast. Pearson´s correlation was used to test for relationship between imaging parameters and AGD.

Results

the mean AGD per exposure was 1.9 ± 0.7 mGy for CC projections and 2.3 ± 1.2 mGy for ML projections. The mean AGD per examination for the study was 4.1 ± 1.4 mGy. A positive correlation was found between AGD per examination and exposure factors (tube loading and tube voltage), compressed breast thickness, and compression force. Patient age had no statistically significant relationship with the AGD per examination.

Conclusion

average glandular dose (AGD) was consistent with other findings in literature studies. It was also observed that MEC yielded lower AGD per exposure values than AEC. There was no significant difference in the mean AGD per exposure for left and right breasts.

Dosimetric Study of Heat-Treated Calcium-Aluminum-Silicon Borate Dosimeter for Diagnostic Radiology Applications

The production of thermoluminescence (TL) dosimeters fabricated from B₂O₃-CaF₂-Al₂O₃-SiO₂ doped with Cu and Pr for use in diagnostic radiology is the main goal of this research. The TL samples were synthesized via the melt-quench technique processed by melting the mixture at 1200 °C for 1 h, and, after cooling, the sample thus created was divided into two samples and retreated by heating for 2 h (referred to as TLV30) and for 15 h (referred to as TLV17). SEM and EDS analyses were performed on the TL samples to confirm the preparation process and to investigate the effects of irradiation dosimetry on the TL samples. Furthermore, the TL samples were irradiated with γ-rays using a 450 Ci ¹³⁷Cs irradiator and variable X-ray beams (5-70 mGy). Two important diagnostic radiology applications were considered: CT (6-24 mGy) and mammography (2.72-10.8 mGy). Important dosimetric properties, such as the glow curves, reproducibility, dose-response linearity, energy dependence, minimum dose detectability and fading, were investigated for the synthetized samples (TLV17 and TLV30), the results of which were compared with the Harshaw TLD-100. The TLV17 dosimeter showed higher sensitivity than TLV30 in all applied irradiation procedures. The dose-response linearity coefficients of determination R² for TLV17 were higher than TLD-100 and TLV30 in some applications and were almost equal in others. The reproducibility results of TLV17, TLV30 and TLD-100 were less than 5%, which is acceptable. On the other hand, the results of the fading investigations showed that, in general, TLV17 showed less fading than TLV30. Both samples showed a significant decrease in this regard after the first day, and then the signal variation became essentially stable though with a slight decrease until the eighth day. Therefore, it is recommended to read the TL dosimeters after 24 h, as with TLD-100. The SEM images confirmed the existence of crystallization, whilst the EDS spectra confirmed the presence of the elements used for preparation. Furthermore, we noticed that TLV17 had grown dense crystals that were larger in size compared to those of TLV30, which explains the higher sensitivity in TLV17. Overall, despite the fading, TLV17 showed greater radiation sensitivity and dose-response linearity compared with TLD-100. The synthetized TL samples showed their suitability for use as dosimeters in diagnostic radiology radiation dosimetry.

THE IMPORTANCE OF FEEDBACK IN MONITORING PATIENTS' RADIATION DOSES IN MAMMOGRAPHY

The majority of medical facilities in the Slovak Republic archive diagnostic images of their patients in a picture archiving and communicating system (PACS). Data from the PACS system can be used to analyse patient radiation dose and perform internal and external quality control through dose monitoring software systems. However, appropriate use of such systems requires the provision of feedback and the ability of staff to identify causes of diagnostic reference level exceedances. The present pilot study evaluated the use of a Dose quality control system (DQC) for monitoring the radiation dose of the patients in the ongoing mammography screening, with subsequent identification of alerts triggered by the system.