THE IMPACT OF X-RAY UNIT TYPE USED FOR ENDOSCOPIC RETROGRADE CHOLANGIOPANCREATOGRAPHY PROCEDURES ON PATIENT DOSES.

To investigate whether the X-ray unit type used for interventional endoscopic retrograde cholangiopancreatography (ERCP) procedures may affect patient radiation doses. A total of 471 ERCP procedures performed in 4 hospitals with 4 types of X-ray units were studied. Kerma-area product (KAP), fluoroscopy time (T) and total number of radiographs acquired (F) were recorded. KAP, T and F values exhibited a great variation, ranging from 0.1 to 130.2 Gy cm2 (mean 16 Gy cm2), 0.13 to 33.7 min (mean 5.4 min) and 0 to 26 radiographs (mean 3.5), respectively. The respective mean values for the four types of X-ray units that were investigated were as follows: KAP: 17.4, 12.5, 5.6 and 36.3 Gy cm2, T: 4.7, 5.2, 3.8 and 11.5 min and F: 1.7, 7.4, 1.9 and 4.6 radiographs. The type of the X-ray unit seems to significantly affect patient radiation dose, with the C-arm delivering the lowest and the angiography unit the highest patient doses.

Preliminary diagnostic reference levels for endoscopic retrograde cholangio-pancreatography in Greece.

The main objective of this study was to determine the preliminary Diagnostic Reference Levels (DRLs) in terms of Kerma Area Product (KAP) and fluoroscopy time (Tf) during Endoscopic Retrograde Cholangio-Pancreatography (ERCP) procedures. Additionally, an investigation was conducted to explore the statistical relation between KAP and Tf. Data from a set of 200 randomly selected patients treated in 4 large hospitals in Greece (50 patients per hospital) were analyzed in order to obtain preliminary DRLs for KAP and Tf during therapeutic ERCP procedures. Non-parametric statistic tests were performed in order to determine a statistically significant relation between KAP and Tf. The resulting third quartiles for KAP and Tf for hospitals (A, B, C and D) were found as followed: KAPA=10.7Gycm(2), TfA=4.9min; KAPB=7.5Gycm(2), TfB=5.0min; KAPC=19.0Gycm(2), TfC=7.3min; KAPD=52.4Gycm(2), TfD=15.8min. The third quartiles, calculated for the total 200 cases sample, are: KAP=18.8Gycm(2) and Tf=8.2min. For 3 out of 4 hospitals and for the total sample, p-values of statistical indices (correlation of KAP and Tf) are less than 0.001, while for the Hospital A p-values are ranging from 0.07 to 0.08. Using curve fitting, we finally determine that the relation of Tf and KAP is deriving from a power equation (KAP=Tf(1.282)) with R(2)=0.85. The suggested Preliminary DRLs (deriving from the third quartiles of the total sample) for Greece are: KAP=19Gycm(2) and Tf=8min, while the relation between KAP and Tf is efficiently described by a power equation.