A study presented at the Society for Minimally Invasive Spine Surgery Global Forum in 2014 examined how C-arm positioning affects radiation exposure.
The study included 270 minimally invasive spine surgeries with set-up radiation recorded. The procedures took place at two separate locations. Thirty of the procedures were thoracic and 240 were thoracolumbar or lumbar; 78 cases were anterior and 192 cases were posterior.
The researchers found:
1. Average radiation for the whole procedure was 8.04 rad, including set up, positioning and surgery.
2. The average set up radiation dose was 1.9 rad, 28 percent of the total radiation dose. However, in cases involving just the thoracic spine, the set up radiation dose was 3.07 rad, 52 percent of the entire radiation dose of 7.08 rad on average.
3. Set-up for lumbar and thoracolumbar cases accounted for 25 percent of the total radiation dose on average. The set-up dose was 1.76 rad of the 8.16 rad total.
4. The thoracic cases had more overall radiation during the set up portion of the case.
5. The total percentage of radiation during positioning was more than a quarter of the total radiation exposure, and was "not insignificant" for any case except simple decompressions.
"Everyone in the OR including ancillary personnel should recognize the high percentage of radiation that occurs during positioning of a C-arm and merit should be given to technologies that can help limit unnecessary radiation exposure during this portion and not simply during the intervention itself," concluded the study authors.