Establishment of local diagnostic reference levels for pediatric chest radiography using Monte Carlo–estimated incident air kerma: A multicentre study in Casablanca, Morocco

Introduction Diagnostic reference levels (DRLs) are essential for optimizing radiation exposure, particularly in pediatric radiography, where patients are more radiosensitive and imaging practices may vary across institutions. In Morocco, pediatric DRLs for chest radiography remain insufficiently documented. This study aimed to establish local diagnostic reference levels (LDRLs) for pediatric chest radiography using incident air kerma (IAK) estimated via Monte Carlo–based methods. Methods A total of 116 pediatric chest radiographs from patients aged from birth to less than 18 years were collected from four hospitals. Patient demographics and scan parameters (kVp, mAs, and focus-to-detector distance (FDD)) were recorded. IAK values were estimated using CALDOSE_X software. Age-specific DRLs were determined, and the LDRL was defined as the 75th percentile of hospital median IAK values, in accordance with ICRP Publication 135. Statistical analyses were performed using SPSS with Bonferroni correction applied for repeated group comparisons (adjusted α = 0.006). Comparisons with international DRLs were conducted for contextual benchmarking. Results DRLs generally increased with age, peaking at 1.62 mGy in the 10–14-year group, then decreasing in the oldest group. Hospital-specific median IAK values ranged from 0.16 to 0.43 mGy. The derived LDRL of 0.41 mGy exceeded the selected international reference values. A strong positive correlation was observed between mAs and IAK (r = 0.78, p < 0.001). Significant differences in kVp, mAs, and IAK values were observed across hospitals and remained significant after Bonferroni correction, whereas age-group differences in IAK did not remain statistically significant after correction. Conclusion This study establishes the first set of pediatric chest LDRLs for the Casablanca region and highlights variability in radiation dose and exposure practices that may indicate opportunities for optimization. The proposed values should be interpreted as preliminary local benchmarks. Implications for practice The proposed LDRLs provide a practical benchmark for dose auditing and protocol standardization. Their implementation may help reduce unnecessary dose variability, support quality assurance programs, and contribute to the future development of national pediatric DRLs in Morocco.