Diagnostic reference levels for pediatric chest radiographs at three radiology units in Kampala, Uganda.

Abstract

The optimization of radiation during medical exposures is a very important principle of radiation protection. It is very important in children as they are more sensitive to radiation, with more effective doses, and have higher life expectancy. One way of achieving radiation optimization is by setting typical, local, National or Regional Diagnostic Reference Levels (DRLs). Neither typical nor local nor National DRLs for plain chest radiography in the pediatric population have been established in Uganda. Absence of DRLs could result in unsafe practice which poses detrimental effects on patients and medical personnel. General Objectives: To determine the Typical Diagnostic Reference Levels for pediatric chest radiographs at three Radiology Units in Kampala, Uganda. Methodology: This was a cross-sectional study carried out in three selected hospitals in Kampala, Uganda from February 2022 to April 2022. The demographic data, clinical indications, and anatomic site was examined of 177 patients whose request forms were collected. The x-ray machine specifications, specific type of CXR examination, and acquisition doses were collected from the x - ray console. The data collected was analyzed to determine the median of the Entrance surface dose (ESD), and Effective Dose (ED) to establish the typical Diagnostic Reference Level for the three Radiology Units in Kampala. The typical DRLs were compared with international published pediatric CXR DRLs and to standard best practice. Results: A total of 177 children who underwent chest radiograph examinations were recruited in this study. The majority of participants in this study were males, 92(52%). Most of the children were aged 1-<5 years (33.3%). The mean Kilovoltage peak (kVp) increased with increase in levels of age category from 63.1±9.7 in children aged 0-<12 months to 107±32.2 in those aged 15-<18 years. However, it was observed in table 13 below that the maximum mAs was high in age categories of 1-<5 years (min-2.0, max-13.5) through to age category 15-<18 years (min1.1, max-120.3). The minimum focus to film distance was 100 cm and maximum 150 cm. The median ESD was not statistically significantly different when compared between male and female (p-0.357). However, the median ESD was statistically significantly different when compared among the age categories and radiology units (p < 0.001). Radiology Unit 2 had the highest ESD of 0.118 mGy, IQR (0.035-0.653), followed by Radiology Unit 3, ESD of 0.060 mGy, IQR (0.035-0.076) and the lowest at Radiology Unit 1, ESD of 0.044 mGy, IQR (0.0380.051). The median ESD/ Facility Reference Level (FRL) for pediatric chest x-ray examinations at RU 3 was 0.062 for the age category of 0-<1 year, 0.063 for the age category 1-<5 year, 0.059 for the age category of 5-<10 years, 0.037 for the age category of 10-<15 years and 0.027 for the age category of 15-<18 years. The median ED was statistically significantly higher in Radiology Unit 2 than Radiology Units 1 and 3, p-<0.001. Conclusion: The median ESD/ Facility Reference Level (FRL) at RU 3 for this study were 0.062 mGy for the age category 0-<1 year, 0.063 mGy for the age category 1-<5 years, 0.059 mGy for the age category 5-<10 years, 0.037mGy for the age category 10- <15 years and 0.027 mGy for the age category 15-<18 years.