Indication based typical diagnostic reference level for barium swallow examination at three centres in Kampala, Uganda

Abstract

Introduction: There is reduction in the utilization of barium examination which is attributable to concerns regarding the excessive exposure of ionizing radiations. Diagnostic Reference Levels (DRLs) are employed in identifying unusually high doses of radiation for specific radiological examinations so that corrective action can be taken. Indication based DRLs for the commonly performed radiological examinations are not established in many African countries, Uganda inclusive. Objective: The main aim of the study was to determine the Typical Diagnostic Reference Level for barium swallow examination of patients with dysphagia at three centres in Kampala, Uganda. Methodology: It was a cross sectional, descriptive and analytical study conducted from July 2023 to December 2023. It involved adult patients with dysphagia, who underwent barium swallow examination at three Centers located within Kampala-Uganda. The study had a total of 90 patients who were consecutively recruited. The exposure parameters were recorded and used to calculate radiation doses received by patients, from which the 50th percentile was derived as the Typical diagnostic reference level that was later compared to those from other countries. The relationship between radiation doses and patient characteristics was also established. RESULTS: A total of 90 patients were recruited in the study with an average age of 48 years, of these 48 (53%) were male. The overall mean kVp was 69.4 Kv and there was a statistically significant difference in the mean kVps between the 3 centres (p=.0.001). The overall mean mAs was 27.1mAs, however, there was no statistically significant difference in the mean mAs between the 3 centres (p = 0.0197). The overall mean Fluoroscopic time was 2.5 minutes and there was a statistically significant difference in the mean fluoroscopic time between the 3 centres (p-value =0.001). The overall mean of outcome dose area products was 6.4 Gycm2 and the difference between the mean doses of the three centres was statistically significant (p-value=0.006). There was a statistically significant (p = 0.002) positive relationship between radiation doses (M et al.) and BMI. There was a negative relationship between radiation doses and age, however, this was only statistically significant at bivariate analysis. There was no significant relationship between sex and radiation doses. The median outcome doses area product was 5.7Gycm2 which was the Indication based Typical DRL for the barium swallow examination. The typical DRL was less than the Typical DRLs from the Brazil, South Africa and Germany studies (41,7.2 and 6.1) Gycm2 respectively but higher than the Typical DRLs from the United Kingdom studies (1.4Gycm2 and 3.5 Gycm2). Conclusion. There were significant differences in exposure factors between the different centres and there was also a significant positive relationship between radiation doses received by patients and their BMI. The indication based Typical DRL value for barium swallow examination was established in Uganda for the first time, laying a foundation for understanding the status of fluoroscopic radiation doses received by particular patients undergoing particular examinations. Recommendation. The Typical DRL established in this study should be adopted by centres/hospitals for dose optimization in barium swallow examination. All imaging centres should review their exposure factors in order to optimise radiation doses received by patients undergoing fluoroscopic examinations.