A drape cuts radiation exposure during cholangiopancreatography

Last Updated: 2015-04-09

By Lorraine L. Janeczko

NEW YORK (Reuters Health) - During endoscopic retrograde cholangiopancreatography (ERCP), using a drape around the image intensifier that reduces radiation scatter cuts the staff's radiation exposure by 90% or more, a new study suggests.

Radiation exposure to staff performing ERCP can be high in high-volume centers, yet many endoscopists don't wear all the recommended protective gear. A radiation-attenuating drape helps decrease radiation exposure to acceptable levels, the authors wrote in their study published online March 31 in the American Journal of Gastroenterology.

"We were very impressed with the study results. Scatter radiation is the main source of exposure for the endoscopists and the study drape was able to achieve this high level of protection by blocking the scatter," Dr. Thiruvengadam Muniraj, of the Yale School of Medicine in New Haven, Connecticut, told Reuters Health by email.

"Over the past few years there has been an increasing emphasis on quality metrics in endoscopy, which includes quality in ERCP. Minimization of radiation exposure is an important quality goal in ERCP. Endoscopists in high-volume centers and those who do more complex cases with higher fluoroscopy time are at risk of exceeding the annual safe limits of radiation exposure despite using the traditional lead gear," he added.

Dr. Muniraj and colleagues analyzed 100 consecutive therapeutic ERCPs at one academic tertiary care center. In random order, during 50 procedures, lead-free radiation-attenuating drapes were suspended around the fluoroscopy image intensifier, and during another 50 procedures, identical sham drapes were used.

The disposable intervention RADPAD drapes (Worldwide Innovations & Technologies), made of the heavy metals bismuth and antimony, were adhesive, sterile, lead-free, disposable, weighed less than 150 grams/5.3 ounces and measured 11 x 34 inches. They had been shown to reduce scatter radiation considerably during procedures for other conditions, the authors wrote.

The sham drapes provided by the same manufacturer were made of rubber but did not contain any heavy metals. All drapes used in the study were packaged in sterile covers with only a bar code for identification.

The researchers measured the effective radiation dose at the endoscopist's eye and neck and at the assisting nurse's neck, and they estimated the cumulative annual radiation exposure. All endoscopists and nurses in the study used conventional radiation protection with a lead apron, thyroid shield, and lead glasses.

Fluoroscopy time, absorbed radiation dose, and dose area product were similar in both groups. The mean effective dose for radiation-attenuating versus sham drape was 0.02 versus 0.21 millisieverts (mSv) at the endoscopist's eye, 0.03 versus 0.35 mSv at the endoscopist's neck, and 0.02 versus 0.27 mSv at the nurse's neck (p<0.0001 for all comparisons).

At the endoscopist's eye and neck and the nurse's neck, the relative risk reductions in radiation were 90%, 91%, and 93%, respectively. At high-volume centers where an endoscopist performs 500 therapeutic ERCPs per year, the estimated cumulative annual effective dose at eye level is 126 mSv with conventional protection compared with 12 mSv when a radiation-attenuating drape is added.

"This is a relatively a new area of research, and no trials have definitively addressed the reduction of radiation exposure to endoscopists using such simple drapes," senior author Dr. Priya A. Jamidar, also of the Yale School of Medicine, told Reuters Health by email.

"The idea of using such a radioprotective drape will alleviate anxiety among many endoscopists performing ERCPs, especially those who perform high volumes and complex cases with higher fluoroscopy times," he said.

The International Commission on Radiological Protection recommends a maximum safe limit for effective dose of 20 mSv/year averaged over a five-year period, with no single year exceeding 50 mSv, for the whole body and the eye.

The authors reported no external funding and no conflicts of interest.

Source: http://bit.ly/1HVO2fd

Am J Gastroenterol 2015.