Radioprotection 61-2 | Page 53

122 M. Azeddou et al.: Radioprotection 2026, 61( 2), 121 – 125 Table 1. Values of the Mean, median, and 3rd quartile of the distribution of Air KERMA( K air), Dose Area Product( DAP), and fluoroscopy time( FT) for four interventional procedures( LLA, CA, CVAD, PM).

common IR procedures at the Mohammed VI University Hospital Center in Marrakech, Morocco.

2 Material and methods

A retrospective study was conducted in the medical Imaging department at the Mohammed VI University Hospital Center in Marrakech, between January and December 2024. The Cath-lab station included two rooms, one exploited by radiologists and the second belong to cardiology department. The angiography systems used were a Siemens Artis Zee, equipped with a flat panel detector. The study focused on IR guided procedures performed by radiologists and the cardiac procedures were excluded.

The sample included the most frequent IR procedures in 2024: Lower limb angiography( LLA), cerebral angiography( CA), Central venous access devices( CVAD), Pacemaker implantation( PM). Following ICRP recommendations, we manually extracted DAP, FT and K air from the Digital Imaging and Communications in Medicine( DICOM) header( Vañó et al., 2017). A total of 220 of diagnostic procedures were included in this study. To further ensure accuracy, the X-ray system’ s maintenance and calibration reports were reviewed, confirming that all quality control measures were up to date.

Data analysis was performed using Microsoft Excel 2017. The descriptive statistics were exploited to determine the mean, median, and 3 rd quartile values of dose distributions, including DAP, FT, and K air. The local DRLs were defined as the 3 rd quartile. The derived local DRLs were compared to published studies DRLs.

3 Results

A total of 220 procedures were recorded at a single machine. Patient ages ranged between 20 and 80 yr. Table 1 presents four interventional procedures: LLA, CA, CVAD and PM. The key parameters reported include K air in Gy, DAP in Gy · cm 2 and FT in minutes. The results are given in terms of mean, median, and 3rd quartile values.

For LLA procedures, the mean K air was 0.30 Gy, with a median of 0.21 Gy and a 3rd quartile value of 0.47 Gy. The mean DAP was 81.38 Gy · cm 2, with a median of 59.34 Gy · cm 2 and a 3rd quartile of 107.98 Gy · cm 2. DAP and K air exceed those of other procedures, which indicate that some cases involve significantly higher exposure. Comparing to the other procedures, FT remains relatively low, with a mean of 2.69 min and a median of 1.1 min.

For CA procedures, the mean K air was 0.88 Gy, with a median of 0.78 Gy and a 3rd quartile of 1.08 Gy. The mean DAP was 196.61 Gy · cm 2, with a median of 184.93 Gy · cm 2 and a 3rd quartile of 232.18 Gy · cm 2. FT was significantly higher than other procedures, with a mean of 9.69 min, a median of 6.80 min, and a 3rd quartile of 11.40 min. These results indicate that CA procedures require prolonged fluoroscopic guidance, contributing to increased patient dose.

For CVAD procedures, radiation exposure was minimal. The mean K air was 0.00871 Gy, with a median of 0.0046 Gy and a 3rd quartile of 0.0075 Gy. The mean DAP was 2.50 Gy · cm 2, with a median of 1.11 Gy · cm 2 and a 3rd quartile of 2.26 Gy · cm 2. FT was the shortest among all procedures, with a mean of 0.79 min, a median of 0.56 min, and a 3rd quartile of 1.15 min. These values confirm that CVAD involves low radiation exposure, likely due to the relatively simple nature of the procedure.

For PM procedures, the mean K air was 0.10 Gy, with a median of 0.09 Gy and a 3rd quartile value of 0.13 Gy. The mean DAP was 20.74 Gy · cm 2, with a median of 16.87 Gy · cm 2 and a 3rd quartile of 27.10 Gy · cm 2. FT remains relatively high, with a mean of 6.95 min and a median of 5.90 min and a 3rd quartile of 7.98 min.

4 Discussion

The purpose of assessing Diagnostic Reference Levels( DRLs) was to pinpoint facilities where radiation protection practices may need further review to ensure optimization for patients and staff. This study may serve as a foundational step toward establishing national DRLs. Given the absence of national DRL guidelines in Morocco. Table 2 compares our local Diagnostic Reference Levels( DRLs) for four interventional procedures LLA, CA, CVAD, and PM based on DAP, FT, and Kair with values reported in previously published studies.

The findings indicate that CA procedures result in the highest radiation exposure across all three parameters( DAP, FT, and K air). The high DAP values( 196.61 Gy · cm 2) in these procedures suggest extended fluoroscopic guidance and multiple image acquisitions to ensure precise catheter navigation. The prolonged FT( mean = 9.69 min) was consistent with the complexity of CA interventions, which require meticulous positioning to minimize procedural risks. Consequently, the high K air values( mean = 0.88 Gy) indicate substantial radiation exposure to patients. However, CVAD procedures inherently demonstrate the lowest radiation exposure values.