Diagnostic Reference Levels in Digital Mammography in Singapore General Hospital (SGH) and Sengkang General Hospital (SKH).

Breast cancer is the most common malignancy amongst females in Singapore and regular mammography screening is an effective way to reduce mortality. However, due to its involvement of ionising radiation, the International Commission of Radiation Protection (ICRP) recommends the establishment of diagnostic reference levels (DRLs) to ensure that radiation dose is kept as low as reasonably possible. DRLs are benchmarks which allow for corrective measures to be implemented if audit levels are found to differ greatly from established standards, preventing dose creep.3,4 In mammography, the DRL should be derived from the mean glandular dose (MGD), which refers to the mean dose absorbed by the radiosensitive glandular breast tissue.3,5-7 As breast compositions can vary significantly between populations, it is important to establish a DRL specific to Singapore’s population, As per ICRP’s recommendations. To date, there has not been any DRLs established for digital mammography in Singapore. In this study, institutional DRLs for SGH and SKH are established as the first step towards a national DRL.