Evaluation of patient doses for routine digital radiography procedures toward establishing an institutional diagnostic reference levels: A case study in Sri Lanka

Abstract

The present study was conducted as part of a comprehensive work to establish National Diagnostic Reference Levels (NDRLs) in Sri Lanka for the first time. DRLs can be used as an effective optimization tool for identifying unusually high or low patient doses during X‐ray examinations. This study aims to propose institutional DRLs (IDRLs) by measuring the kerma‐area product (KAP) of adult patients undergoing routine projection X‐ray examinations. The median and the 75th percentile KAP values obtained were compared with that of the single institution KAP values reported from India and Greece. This descriptive cross‐sectional study was conducted in a public hospital in Uva province, Sri Lanka, with 400 adult patients aged 18–87 years and weighing 58 ± 20 kg. The patient‐specific information (age, sex, weight, and height) and corresponding exposure parameters (tube voltage and current‐exposure time product) were obtained. The KAP values were measured, and descriptive statistics were utilized for data analysis. The median KAP values obtained were proposed as IDRLs. The IDRLs in Gy.cm2 were 0.23 for cervical spine anterior–posterior (AP), 0.19 for cervical spine lateral (LAT), 0.10 for chest posterior–anterior (PA), 0.06 for knee joint AP, 0.05 for knee joint LAT, 1.47 for KUB AP, 0.85 for lumbar spine AP, 1.97 for lumbar spine LAT, 0.29 for shoulder joint AP, 0.61 for skull PA, and 0.60 for skull LAT examinations. The maximum to minimum ratio of KAP values ranged from 2.4 for KUB AP to 6.3 for the cervical spine AP examinations. The median and the 75th percentile of most of the examinations were comparable to corresponding KAP values reported by the countries mentioned above, except for the skull PA and LAT examinations. Accordingly, interquartile ranges of exposure parameters are recommended for skull examinations to improve the optimization of patient doses.

Towards the establishment of national diagnostic reference levels for abdomen, KUB, and lumbar spine x-ray examinations in Sri Lanka: a multi-centric study

“…IDRLs were determined as the 50th percentile of the P KA distribution in each hospital [24]. ADs were defined as the 50th percentile of the median P KA values for all hospitals, while MCDRLs were set as the 75th percentile of the median P KA values for all hospitals [19,25].…”

“…Furthermore, the lack of institutional or national criteria for radiographic practice could also contribute to these variations. Notably, two hospitals (HC and HE) did not adhere to the minimum filtration requirement of 2.5 mm aluminium (Al) for peak tube voltages exceeding 70 kVp [24,30]. Therefore, it is recommended to maintain the minimum filtration requirement in those hospitals.…”

“…Substantial variations in IDRLs were found across hospitals for all four examinations. These baseline dose levels facilitate inter-hospital comparisons and provide a starting point for institutional dose optimisation [24]. However, the variations in IDRLs are still substantial, indicating that there is a need to reduce patient doses in those hospitals at the upper end of the dose range.…”

“…Sri Lanka has seen a rapid increase in medical imaging facilities and the number of annual medical imaging examinations mainly due to the increasing population of older citizens [4,5]. Consequently, several efforts have been made previously to optimise these procedures, but the country still needs to adopt NDRLs [24,25]. Furthermore, there is a lack of DRLs for abdomen, KUB, and lumbar spine x-ray examinations.…”

Towards the establishment of national diagnostic reference levels for chest x-ray examinations in Sri Lanka: a multi-centric study

“…In reality, being a lower middle-income country, hospitals in Sri Lanka have MEC mode x-ray systems due to economic constraints. Nevertheless, only recently has an IDRL for a single hospital in one of the provinces in Sri Lanka been recommended [18]. Therefore, the present study aimed to propose the multi-centric diagnostic reference level (MCDRL) for chest x-ray examinations in adults in Sri Lanka.…”