Establishing a national diagnostic dose reference level in digital mammography and digital breast tomosynthesis in Jordan with emphasis on breast density.

Introduction: Diagnostic reference levels (DRLs) are one of the most important radiation protection methods in medical imaging to help optimize radiation exposure during imaging procedures. The study aimed to establish national DRL for digital mammography (DM) and digital breast tomosynthesis (DBT) in Jordan, considering variations in compressed breast thickness (CBT) and breast density.

Methodology: The exposure parameters, average glandular dose (AGD), CBT, breast density, and viewing projection were extracted. The mean, median, 75th, and 95th percentiles were obtained for the AGD distribution of each projection for DM and DBT at three CBT ranges and two density categories. The difference in AGD between DM and DBT was determined.

Results: The proposed national DRLs in Jordan for DM in CC view were 2.29, 1.78, and 2.40 mGy, while for MLO view were 1.17, 1.47, and 2.02 mGy at CBT ranges of 4-39, 40-59, 60-99 mm, respectively. For DBT in CC view, the DRLs were 2.17, 2.69, and 3.52 mGy, while in MLO view, the DRLs were 2.29, 2.67, and 3.49 mGy for the respective CBT ranges. The overall AGD of DBT was significantly higher compared to DM (P < 0.05). The AGD of high-density breasts was higher than low-density breasts for both DM and DBT (P < 0.001).

Conclusion: The proposed national DRLs in Jordan were higher than those reported in the literature, with AGD higher for DBT than that of DM.

Implications For Practice: Although the DRLs in Jordan remain below the International Atomic Energy Agency (IAEA) reported DRL, the fact that they exceed the previously established DRLs indicates a need for rigorous calibration and dose optimization methods to minimize unnecessary exposures, particularly in hospitals where the DRLs were near the DRLs set by the IAEA.