What are the fluoroscopic on-time benchmarks for cervical facet and intra-disc injections?

Fluoroscopic On-Time Benchmarks for Cervical Facet and Intra-disc Injections

Based on current evidence, fluoroscopic on-time for cervical facet and intra-disc injections should be minimized to less than 15 pulses per second, with total fluoroscopy time ideally kept under 30 minutes to reduce radiation exposure risk. 1

Radiation Safety Parameters for Cervical Spine Procedures

Pulse Rate and Exposure Recommendations

• Use pulsed fluoroscopy at the lowest rate that provides adequate visualization (≤15 pulses/second)
• Lower pulse rates (10,7.5, or 3.5 pulses/second) may be adequate for many procedures 1
• Start with "low-dose" fluoroscopy mode and only increase if necessary for visualization

Time Benchmarks

• Fluoroscopy time should be monitored and minimized
• For comparison, Mayo Clinic benchmarks for cardiac procedures show:
  • Left heart catheterization: median 5.8 minutes
  • Percutaneous coronary intervention: median 15.7 minutes 1
• While specific benchmarks for cervical procedures aren't established in guidelines, exceeding 30 minutes of fluoroscopy time (especially with older equipment) or 50 minutes (with modern equipment) warrants patient follow-up for potential radiation injury 1

Dose Monitoring Parameters

• Monitor both:
  1. Total air kerma at the interventional reference point
  2. Total procedure kerma-area product (KAP) 1
• Patient skin doses exceeding 5 Gy should trigger follow-up protocols 1
• The Joint Commission considers skin entrance doses >15 Gy as a reviewable sentinel event 1

Techniques to Minimize Radiation Exposure

Equipment Positioning

• Position the X-ray source and image receptor optimally
• Minimize distance from patient to image detector
• Raise table to increase distance between radiation source and patient 1

Beam Management

• Use active collimation to limit X-ray beam size to minimum area needed
• Never use fluoroscopy with collimator leaves wide open 1
• Remove extraneous body parts from the imaging field of view 1

Procedural Techniques

• Use last image hold and last fluoro loop features to avoid unnecessary fluoroscopy
• Minimize acquisition runs to only what's necessary for diagnosis and treatment
• Never irradiate the patient unless the operator's eyes are on the monitor 1
• For longer procedures, vary the site of radiation entrance port to distribute skin dose

Specific Considerations for Cervical Procedures

Anatomical Factors

• CT fluoroscopy-guided cervical injections have shown high accuracy (92-98%) 2
• For cervical facet injections, the most commonly accessed levels are C3-4 (40%) and C4-5 (33%) 2
• For cervical interlaminar injections, C5-C6 is the most preferred intervention level 3

Clinical Outcomes

• Injectate spread patterns affect clinical outcomes:
  • Targeting extraforaminal or juxta-articular facet space improves clinical efficacy 4
  • Epidural spread during transforaminal injections is less effective for pain relief 4

Quality Assurance Considerations

• Implement monitoring of both fluoroscopy time and patient dose metrics
• Review procedures that exceed dose thresholds (>5 Gy)
• Establish follow-up protocols for patients receiving higher radiation doses
• Consider patient follow-up at 1 and 3 months post-procedure if fluoroscopy time exceeds benchmarks 1

By adhering to these guidelines, clinicians can minimize radiation exposure while maintaining adequate visualization for safe and effective cervical facet and intra-disc injections.