Radiation Reduction Using Image Enhancement Technology Better Than ALARA Practice Alone In Lateral, Single-Position Lumbar Surgery
Presented at SMISS Annual Forum 2019
By Brett Braly MD
With Sam Hasan RT,
Disclosures: Brett Braly MD A; NuVasive. Sam Hasan RT None,
As the use of minimally invasive surgical (MIS) techniques for spinal surgery has expanded, so has the reliance on intraoperative fluoroscopic imaging for anatomic identification as well as to visualize procedural steps. While MIS procedures have generally benefited patients with lower morbidity and faster return to normal function, the operating room (OR) staff and surgeons are thought to be exposed to significantly more radiation in these cases, which can lead to elevated rates of a variety of, and sometimes terminal, disease.
The purpose of this study was to evaluate radiation emission and surgical workflow differences between lumbar interbody fusion procedures performed with intraoperative fluoroscopic use at standard ALARA-dose versus ALARA-dose settings with software-enhancement of image quality and incorporation of surgical workflow efficiency tools.
A retrospective review of prospectively collected data was undertaken from a single site. A total of 68 patients were treated with single-level or 2-level lumbar interbody fusion: 34 with ALARA-dose fluoroscopic setting and 34 with low-dose capture and real-time image enhancement (LessRay, NuVasive, Inc.). The image enhancement software also included surgical efficiency tools (e.g., tracking to reduce/eliminate scouting shots). All patients were treated in the lateral position for both interbody fusion and bilateral pedicle screw and rod fixation. Interbody fusion was performed using either transpsoas lateral interbody fusion (XLIF, NuVasive, Inc.) or lateral-position anterior lumbar interbody fusion (ALIF) approaches. Screws were placed percutaneously in all cases.
All cases were successfully performed with the patient maintained in the lateral position for both interbody fusion and bilateral pedicle screw fixation. Mean total operative C-arm radiation emission was found to be significantly lower in the image-enhanced group compared to the standard ALARA-dose group: 33.3 milligray (mGy; standard deviation [std]: 18.4 mGy) vs. 52.2 mGy (std: 36.8 mGy), respectively (p<0.01). Mean total fluoroscopy time was found to be significantly lower in the image enhanced group compared to the standard-dose group: 110.6 seconds (std: 42.61 seconds) vs. 166.9 seconds (std: 51.87 seconds), respectively (p<0.0001). The effect of using intraoperative image enhancement of low-dose fluoroscopic images on both radiation emission and fluoroscopy time remained a significant factor when controlled for age, sex, BMI, procedure (XLIF vs. ALIF), and number of levels (single- vs. 2-level).
Compared to ALARA-dose settings alone, the results of this preliminary comparative study suggest that using software enhancement of low-dose fluoroscopic images to perform lateral-position interbody fusion and posterior fixation reduces both radiation emission and fluoroscopic time.