Radiation dose in cone beam CT guided ERCP

Abstract

Purpose: To evaluate the practical and radiation safety considerations in utilization of 3-D imaging through cone beam computed tomography (CBCT) in endoscopic retrograde cholangiopancreatography (ERCP).

Method: ERCP procedures were performed using an Artis Q interventional suite (Siemens Healthineers), including 42 procedures with CBCT. Some CBCT cases used the standard "DR" exposure protocol and some used the low dose protocol "DR care". Data on x-ray radiation doses were retrospectively collected and to help optimize technical factors surrounding the procedure and compared to radiation exposure data of patients undergoing conventional ERCP.

Results: The median dose area product was 24.4 Gycm² for one DR volume and 5.07 Gycm² for one DR care volume. The median total dose area product was 6.52 Gycm² for conventional ERCP, 48.9 Gycm² for procedures using DR and 19.7 Gycm² when using DR care. Conventional ERCP resulted in a significantly lower radiation dose than procedures using either CBCT protocols (p < 0.001). However, conventional ERCP showed a large number of outliers with higher dose at the level of, or surpassing, CBCT procedures.

Conclusions: For less complex procedures with small x-ray doses and short fluoroscopy times conventional 2-D x-ray technique is clinically sufficient and utilizes less radiation dose than CBCT methods, but there is a wide range of doses and extreme outliers have been observed. CBCT can facilitate ERCP in cases with difficult ducal anatomy, possibly reducing procedural time, x-ray exposure time and need for contrast injections. Methods for prediction on high radiation ERCPs are needed to standardize and optimize patient selection for CBCT-ERCP.

Keywords: Cholangiopancreatography,Endoscopic retrograde; Cone beam computed tomography; Endoscopy; Fluoroscopy; Gastrointestinal; Imaging, Three dimensional; Radiation dosage.