Diagnostic reference levels in low- and middle-income countries: early "ALARAm'' bells?

Background: In 1996 the International Commission on Radiological Protection (ICRP) introduced diagnostic reference levels (DRLs) as a quality assurance tool for radiation dose optimization. While many countries have published DRLs, available data are largely from high-income countries. There is arguably a greater need for DRLs in low-and middle-income-countries (LMICs), where imaging equipment may be older and trained imaging technicians are scarce. To date, there has been no critical analysis of the published work on DRLs in LMICs. Such work is important to evaluate data deficiencies and stimulate future quality assurance initiatives. Purpose: To review the published work on DRLs in LMICs and to critically analyze the comprehensiveness of available data. Material and Methods: Medline, Scopus, and Web of Science database searches were conducted for English-language articles published between 1996 and 2015 documenting DRLs for diagnostic imaging in LMICs. Retrieved articles were analyzed and classified by geographical region, country of origin, contributing author, year of publication, imaging modality, body part, and patient age. Results: Fifty-three articles reported DRLs for 28 of 135 LMICs (21%), reflecting data from 26/104 (25%) middle-income countries and 2/31 (6%) low-income countries. General radiography (n = 26, 49%) and computerized tomography (n = 17, 32%) data were most commonly reported. Pediatric DRLs (n = 14, 26%) constituted approximately one-quarter of published work. Conclusion: Published DRL data are deficient in the majority of LMICs, with the paucity most striking in low-income countries. DRL initiatives are required in LMICs to enhance dose optimization.