224 R. A. C. Guassu et al.: Radioprotection 2025, 60( 3), 221 – 233 Fig. 2. Outline of interventionists’ position during the vascular intervention procedure. The ceiling and floor shields( SP1 and SP2 in the figure, respectively) were used to protect the interventionists during the operations.
Although the effective dose is traditionally defined for homogeneous irradiation of the entire body, in this study, a correction factor( CFT) is applied to account for the nonhomogeneous exposure conditions typical of interventional radiology. This allows the estimation of the effective dose under non-uniform irradiation, adapting its traditional definition to better reflect radiation distribution in these specific contexts.
EffectiveDoseðE D Þ ¼ X26 w T CF T ED r; T
T
2.6 Effective dose estimation through equipment parameters
P KA is calculated as the product of air kerma and beam area( Gy cm 2) and measured using an ionization chamber between the x-ray tube / collimator set up and the patient( International Atomic Energy Agency, 2011)
A factor( f) was obtained for each modality from the normalized effective dose to the P KA values from the equipment, through equation( 4)
f ¼ E
D mSv P KA Gy: cm 2 ð3Þ
ð4Þ
where E D is the average effective dose of each modality, in mSv, and P KA the average P KA of each modality, in Gy cm 2.
The E D was determined as the mean value obtained by equation( 3) for all procedures for each given modality, with P KA being determined in the same manner.
With f values and P KA another estimation of Effective Dose( E f) was calculated for each procedure through equation( 5).
E f ¼ f P KA
2.7 Correlation between effective dose assessment through equipment parameters and dosimetry ð5Þ
Statistical analyses were performed using GraphPad Prism 8( GraphPad Software Inc. San Diego, CA, USA). The median ED r for each body region was calculated by professional and procedure modality. For the same professional and modality, the median ED r values were compared with each other through the Kruskal-Walli’ s test and Dunn’ s multiple comparison test. The null hypothesis states that ED r do not differ between different body regions for a given professional performing procedures of the same modality. For the effective doses, the agreement between the estimated values by factor f( E f) and the experimental values( E D) were analyzed using the Bland- Altman method( Dogan, 2018).
Boxplots( Figs. 3 – 10) represent the interquartile range( IQR), with the horizontal line inside the box indicating the median, the asterisk marking the mean, and the boxes defining the limits between the second and third quartiles.