In order to test this question, a digital Geiger counter was worn on the forehead of one surgeon for one year for all consecutive cases at multiple sites. At the study’s completion after the year of use, there was 1,827 µSv of total exposure from 245 discrete procedures across four intensifier machines and three operating table types. Percutaneous nephrolithotomy (PNL) had a significantly greater amount of radiation to the operator's eyes than any other procedure type (image below). Also, when the data was extrapolated for time, the exposure is well within safe limits, as shown by the line graph below. However, if a particular surgeon has a high output of PNLs at their center, they may potentially exceed safe limits. The choice of image intensifier significantly altered the eye dose with 30% higher doses seen between two different machines that were stratified to the same procedure type and operating table. Dr. Handmer chose to leave out the names of these intensifiers due to legality precautions.
In closing, Dr. Handmer stressed the importance of being aware of the safe limits of ionizing radiation doses in the operating room. He mentioned that the dose area product is not the only determinant of exposure, as the proximity to the image intensifier is important for the operator’s safety. It was shown that some machines do consistently show higher ocular scatter doses regardless of procedure type. Thankfully, exposure was only 9% of the established safe limits. Therefore, Dr. Handmer’s main conclusion was that unless intervention heavy workload, such as a high output of PNLs, no additional protective eyewear is required in the operating room.
Presented by: Marcus Handmer, MD, Hornsby Hospital, Sydney, Australia
Written by: Zachary Valley, Department of Urology, University of California-Irvine, Twitter: @ZacharyAValley, at the 73rd Canadian Urological Association Annual Meeting - June 23 - 26, 2018 - Halifax, Nova Scotia