In gratitude of the loyal support of our members, the CNS is offering complimentary 2021 Annual Meeting registration to all members! Learn more.

  • Accuracy of Patient Registration: Avoiding Use of Multiple Bone Fiducials

    Final Number:
    516

    Authors:
    David J. Donahue MD; Laurie Bailey MD; M. Scott Perry MD; John Honeycutt MD

    Study Design:
    Other

    Subject Category:
    Epilepsy

    Meeting: 2018 ASSFN Biennial Meeting

    Introduction: RATIONALE: Although the robot can be registered to the patient using surface landmark identification, we have come to prefer the accuracy provided by 5 “bone fiducials” affixed to the skull, which entails 9 scalp wounds entailed by 4 Leksell pins plus the 5 fiducials. We reasoned that employing the 4 pins securing the Leksell frame to the skull as fiducial points would obviate 4 of the bone fiducials without compromising accuracy..

    Methods: We quantified localization error,defined as the euclidian distance between planned entry/target points and actual entry/target points, for each SEEG electrode trajectory associated with either Leksell Pin (LP) or “traditional” bone fiducial (BF) registration in the manner described by Gonzalez-Martinez et al.1 Target-point and entry-point errors of 70 consecutive LP-defined trajectories were compared to those seen for 95 consecutive BF-defined trajectories.

    Results: Point errors were seen in 92 FP trajectories and in 67 LP trajectories. Target-point errors (TPE) for the LP group (median = 1.8mm, range 0 – 5.8) were similar to the BF group (median = 1.6 mm, range 0 – 7.8) with a mean difference of -.178t(163) = -1.541, p=.125, (90% CI, -0.369 to 0.013). Likewise, entry-point errors (EPE) for the LP group (median = 1.2, range 0 – 3.2) were similar to the BF group (median = 0.9mm, range 0 – 4.7) with a mean difference of -0.016 t(163) = -0.078, p=.938 (90% CI, -0.347 to 0.315).. Only one of the 67 LP entry-point errors exceeded 3.0 mm; 2 of the 95 BF entry-point errors exceeded 3.0mm.

    Conclusions: The techniques appear equally accurate, but the LP bone fiducial renders placement of 4 bone fiducials unnecessary, potentially reducing OR time and patient discomfort

    Patient Care: Decrease patient discomfort; shorten operative time

    Learning Objectives: Simplify an established technique for stereotactically placing SEEG leads

    References: Gonzalez-Martinez J et al. Technique, Results, and Complications Related to Robot-Assisted Stereoelectroencephalography Neurosurgery 78:2;169-180 (2016).

We use cookies to improve the performance of our site, to analyze the traffic to our site, and to personalize your experience of the site. You can control cookies through your browser settings. Please find more information on the cookies used on our site. Privacy Policy