A new nasopharyngeal dynamic reference frame improves accuracy in navigated skull base targets

Area of Science:

• Neurosurgery
• Medical Imaging
• Surgical Navigation Technology

Background:

• Electromagnetic navigation systems are crucial for cranial procedures.
• The placement of the dynamic reference frame (DRF) can impact navigation accuracy.
• Current standard DRF placement is on the forehead.

Purpose of the Study:

• To evaluate if the position of the DRF affects application accuracy in electromagnetically navigated cranial procedures.
• To compare the accuracy of a nasopharyngeal DRF with a standard forehead-mounted DRF.

Main Methods:

• A novel nasopharyngeal DRF carrier was developed and tested.
• Total target error (TTE) was measured in frontal and lateral skull base regions of human cadaveric heads.
• Comparisons were made using 5 fiducial combinations and 10 targets per site.

Main Results:

• The nasopharyngeal DRF resulted in significantly lower TTE (2.8 ± 1.4 mm) compared to the forehead DRF (3.7 ± 2.8 mm).
• Accuracy improvements were observed at both frontal (3.4 vs 2.1 mm) and lateral (3.9 vs 3.5 mm) skull base sites with the nasopharyngeal DRF.
• The nasopharyngeal DRF demonstrated a 25% improvement in application accuracy.

Conclusions:

• Centrally positioning the DRF in the nasopharynx enhances accuracy in skull base electromagnetic navigation.
• This improved accuracy can lead to better outcomes in cranial procedures.
• The nasopharyngeal DRF offers a significant advancement over traditional forehead placement for electromagnetic navigation.