Evaluation of surgeon and patient radiation exposure by imaging technology in patients undergoing thoracolumbar fusion: systematic review of the literature.

ABSTRACT

BACKGROUND CONTEXT Minimally invasive spine techniques are becoming increasingly popular owing to their ability to reduce operative morbidity and recovery times. The downside to these new procedures is their need for intraoperative radiation guidance. PURPOSE: To establish which technologies provide the lowest radiation exposure to both patient and surgeon. STUDY DESIGN/SETTING: Systematic review OUTCOME MEASURES: Average intraoperative radiation exposure (in mSv per screw placed) to surgeon and patient. Average fluoroscopy time per screw placed. METHODS: We reviewed the available English medical literature to identify all articles reporting patient and/or surgeon radiation exposure in patients undergoing image-guided thoracolumbar instrumentation. Quantitative meta-analysis was performed for studies providing radiation exposure or fluoroscopy use per screw placed to determine which navigation modality was associated with the lowest intraoperative radiation exposure. Values on meta-analysis were reported as mean ± standard deviation. RESULTS: We identified 4956 unique articles, of which 85 met inclusion/exclusion criteria. Forty-one articles were included in the meta-analysis. Patient radiation exposure per screw placed for each modality was conventional fluoroscopy without navigation (0.26±0.38 mSv), conventional fluoroscopy with pre-operative CT-based navigation (0.027±0.010 mSv), intraoperative CT-based navigation (1.20±0.91 mSv), and robot-assisted instrumentation (0.04±0.30 mSv). Values for fluoroscopy used per screw were conventional fluoroscopy without navigation (11.1±9.0 seconds), conventional fluoroscopy with navigation (7.20±3.93 s), 3D fluoroscopy (16.2±9.6 s), intraoperative CT-based navigation (19.96±17.09 s), and robot-assistance (20.07±17.22 s). Surgeon dose per screw conventional fluoroscopy without navigation (6.0±7.9 × 10-3 mSv), conventional fluoroscopy with navigation (1.8±2.5 × 10-3 mSv), 3D Fluoroscopy (0.3±1.9 × 10-3 mSv), intraoperative CT-based navigation (0±0 mSv), and robot-assisted instrumentation (2.0±4.0 × 10-3 mSv). CONCLUSION: All image guidance modalities are associated with surgeon radiation exposures well below current safety limits. Intraoperative CT-based (iCT) navigation produces the lowest radiation exposure to surgeon albeit at the cost of increased radiation exposure to the patient relative to conventional fluoroscopy-based methods.