Background: There is a scarcity of data regarding the radiation dose and as
sociated risks to patients during ERCP. Dose area product (DAP) measurement
s can be used to estimate an effective dose (ED) to patients undergoing ERC
P. This measure allows radiation risk associated with such procedures to be
quantified. The aim of this study was to evaluate the ED to patients under
going ERCP.
Methods: A DAP meter was fitted to the x-ray tube before each ERCP. DAP rea
ding (Gy-cm(2)), fluoroscopy time, average screening kVp, number of films,
and kVp per film were recorded. Mean ED was estimated by using DAP readings
and Monte Carlo computer software to model radiation exposure conditions.
Results: Data were recorded on 20 subjects. Average DAP was 13.5 Gy-cm(2) (
6.8-23.9) for diagnostic and 66.8 Gy-cm(2) (28.7-108.5) for therapeutic ERC
P (p < 0.05). Average fluoroscopy time was 2.3 minutes (1.1-5.3) for diagno
stic and 10.5 minutes (5.9-16.6) for therapeutic ERCP (p < 0.05). DAP showe
d a linear relationship with fluoroscopy time (R-2 = 0.928). Mean number of
diagnostic and therapeutic films was 2.8 and 3.7, respectively. Fluoroscop
ic exposure represented 69% of the DAP for diagnostic ERCP and 90% of the D
AP for therapeutic ERCP. Average ED was 3.1 mSv for diagnostic and 12.4 mSv
for therapeutic ERCP.
Conclusions: Therapeutic ERCP is associated with significantly higher radia
tion exposure than diagnostic ERCP. ED in therapeutic ERCP is a result larg
ely of fluoroscopy time as opposed to number of films.