Predictive Factors of Radiation Dose in ERCP

Abstract

The use of fluoroscopy to aid endoscopic retrograde cholangiopancreatography (ERCP) places both the patient and the endoscopy staff at the risk of radiation-induced injury. Previous reports have demonstrated a linear relationship between radiation dose and fluoroscopy duration. To identify predictive factors of fluoroscopy time and radiation exposure to patients undergoing ERCP by using pulsed fluoroscopy. Four hundred and four consecutive ERCPs performed from January 2010 to November 2010 at 2 tertiary centers in Spain were prospectively studied. Patients and procedural variables were analyzed. Philips BV Pulsera mobile fluoroscopy system was used on the endoscopy unit. Entrance surface dose, dose-area product, and fluoroscopy time were recorded for each patient. A total of 404 ERCPs on 404 consecutive patients were studied (mean age 73 y). The average entrance surface dose and dose-area product were 12.0 mGy and 0.37 mGy/m2, respectively. Mean fluoroscopy time was 2.31 minutes. The biliary ducts were adequately visualized in 371 (92%) cases. After analysis with a univariable model, the factors found to significantly increase the radiation dose (P75>19.6 mGy) were as follows: alkaline phosphatase serum levels (P=0.047), balloon dilation (P=0.005), biliary stent placement (P=0.001), and ERCP diagnosis (P=<0.0001). In a multivariate analysis, only stent insertion significantly increased the radiation dose (risk ratio 4.75; 95% confidence interval, 1.84-7.63). In this prospective analysis, multiple factors affected the radiation dose. Stent insertion was the only independent predictor significantly associated with prolonged fluoroscopy.