Source: DGNews  |  Posted 2 years ago

OAK BROOK, Ill -- April 28, 2009 -- Radiation risks associated with endoscopic retrograde cholangiopancreatography (ERCP) procedures in pregnant women are not trivial and accurate foetal dose estimation is now available regardless of patient body size, operating parameters, equipment used, and gestational stage, researchers stated in a study published in the April issue of GIE: Gastrointestinal Endoscopy.

"Physicians should be able to estimate the foetal dose in all stages of gestation and inform any pregnant patient undergoing ERCP about the actual radiation risks to arrive at a prudent decision regarding the exposed foetus," said lead author John Damilakis, MD, University of Crete, Crete, Greece.

"The findings of this study show that foetal radiation risks associated with fluoroscopically guided ERCP performed on a pregnant patient cannot be disregarded."

"Nonradiation ERCP has been proposed as an alternative, especially for pregnant patients in an effort to decrease potential foetal risks," he continued. "However, further studies are required to prove that the clinical efficiency of nonradiation ERCP remains at the same level with conventional fluoroscopically guided ERCP."

Foetal doses are associated with exposure factors such as kilovolt peak, tube filtration, and the physique of the pregnant woman. National and international radiation protection authorities consider foetal radiation doses up to 1 mGy insignificant, while doses over 10 mGy are considered more relevant.

Dr. Damilakis and colleagues examined the potential for a foetus to receive a radiation dose greater than 10 mGy from the ERCP procedure carried out for the mother and develop a method for the assessment of the foetal dose from ERCP procedures.

They examined 24 consecutive male and non-pregnant female patients who received therapeutic ERCP for conditions including cholangitis, choledocholithiasis, pancreatitis, stent extraction, and pancreatic and bile-duct tumours.

None of the patients were pregnant or suspected of being pregnant, thus no measures to limit radiation exposure were taken.

Based on the radiation exposure in the 24 non-pregnant patients, the radiation dose delivered to a theoretical foetus was then estimated using a Monte-Carlo-N-particle transport code.

The radiation doses estimated for a theoretical foetus in these 24 ERCP procedures ranged from 3.4 to 55.9 mGy. The researchers provided tabulated data that allowed for calculation of the foetal radiation dose.

The data revealed that the foetal dose from ERCP procedures may occasionally exceed 10 mGy, a considerably greater value than previously reported. In cases with pregnant patients, special efforts should be made to minimise the foetal radiation burden.

Researchers noted that limitations of the study included a source of error in the estimation of the foetal dose related to variations of foetus location and size from the average, especially during the second and third trimesters. Another limitation concerns risks related to ionizing radiation.

SOURCE: American Society for Gastrointestinal Endoscopy