Background: The stereoelectroencephalographic (SEEG) implantation procedures still represent a challenge due to the intrinsic complexity of the method and the number of depth electrodes required. Objectives: We aim at designing and evaluating the accuracy of a custom stereotactic fixture based on the StarFix™ technology (FHC Inc., Bowdoin, ME) that significantly simplifies and optimizes the implantation of depth electrodes used in presurgical evaluation of patients with drug-resistant epilepsy. Methods: Fiducial markers that also serve as anchors for the fixture are implanted into the patient's skull prior to surgery. A 3D fixture model is designed within the surgical planning software, with the planned trajectories incorporated in its design, aligned with the patient's anatomy. The stereotactic fixture is built using 3D laser sintering technology based on the computer-generated model. Bilateral rectangular grids of guide holes orthogonal to the midsagittal plane and centered on the midcommissural point are incorporated in the fixture design, allowing a wide selection of orthogonal trajectories. Up to two additional grids can be accommodated for targeting structures where oblique trajectories are required. The frame has no adjustable parts, this feature reducing the risk of inaccurate coordinate settings while simultaneously reducing procedure time significantly. Results: We have used the fixture for the implantation of depth electrodes for presurgical evaluation of 4 patients with drug-resistant focal epilepsy, with nearly 2-fold reduction in the duration of the implantation procedure. We have obtained a high accuracy with a submillimetric mean positioning error of 0.68 mm for the anchor bolts placed at the trajectory entry point and 1.64 mm at target. Conclusions: The custom stereotactic fixture design greatly simplifies the planning procedure and significantly reduces the time in the operating room, while maintaining a high accuracy.

1.
Talairach J, Bancaud J: Stereotaxic exploration and therapy in epilepsy; in Vinken PJ, Bruyn GW (eds): The Epilepsies. Handbook of Clinical Neurology. Amsterdam, North-Holland, 1974, vol 15, pp 758-782.
2.
Talairach J, Bancaud J, Szikla G, Bonis A, Geier S, Vedrenne C: Approche nouvelle de la neurochirurgie de l'épilepsie. Méthodologie stéréotaxique et résultats thérapeutiques. Neurochirurgie 1974;20(suppl 1):243-245.
3.
Talairach J, Szikla G: Application of stereotactic concepts to the surgery of epilepsy. Acta Neurochir Suppl 1980;30:35-54.
4.
Kahane P, Minotti L, Hoffmann D, Lachaux JP, Ryvlin P: Invasive EEG in the definition of the seizure onset zone: depth electrodes; in Rosenow F, Luders H (eds): Handbook of Clinical Neurophysiology. Amsterdam, Elsevier, 2004, vol 3, pp 109-133.
5.
Leksell L: Stereotaxis and Radiosurgery: an Operative System. Springfield, Charles C. Thomas, 1971.
6.
Cosman E: Development and technical features of Cosman-Roberts-Wells (CRW) stereotactic system; in Pell F, Thomas DG (eds): Handbook of Stereotaxy Using the CRW Apparatus. Baltimore, Williams & Wilkins, 1994, pp 1-52.
7.
Guénot M: SEEG electrodes implantation using flat-panel X-ray detectors and robot; in Scarabin M (ed): Stereotaxy and Epilepsy Surgery. Esher, John Libbey Eurotext, 2012, pp 219-244.
8.
Cardinale F, Miserocchi A, Moscato A, Cossu M, Castana L, Schiariti M-P, Gozzo F, Pero G, Quilici L, Citterio A, Minella M, Torresin A, Russo G-L: Talairach methodology in the multimodal imaging and robotics era; in Scarabin M (ed): Stereotaxy and Epilepsy Surgery. Esher, John Libbey Eurotext, 2012, pp 245-272.
9.
Henderson JM: Frameless localization for functional neurosurgical procedures: a preliminary accuracy study. Stereotact Funct Neurosurg 2004;82:135-141.
10.
Franck JI, Konrad PE, Franklin R, Haer F: StarFix™: a novel approach to frameless stereotactic neurosurgery utilizing a miniaturized customized pretargeted cranial platform fixture - technical description, unique features, and case reports. Mov Dis Soc 7th Int Congr of Parkinson Disease and Movement Disorder, Miami, 2002.
11.
Fitzpatrick JM, Konrad PE, Nickele C, Cetinkaya E: Accuracy of customized miniature stereotactic platforms. Stereotact Funct Neurosurg 2005;83:25-31.
12.
D'Haese PF, Pallavaram S, Konrad PE, Neimat J, Fitzpatrick JM, Dawant BM: Clinical accuracy of a customized stereotactic platform for deep brain stimulation after accounting for brain shift. Stereotact Funct Neurosurg 2010;88:81-87.
13.
Stuart R-M: Novel use of a custom stereotactic frame for placement of depth electrodes for epilepsy monitoring. Neurosurg Focus 2008;25:E20.
14.
Frangi AF, Niessen WJ, Vincken KL, Viergever MA: Multiscale vessel enhancement filtering; in Colchester A, Wells WM, Delp S (eds): MICCAI98 Medical Image Computing and Computer-Assisted Intervention (lecture notes in computer science). New York, Springer, 1998, vol 1496, pp 130-137.
15.
Barborica A, Ciurea J, Mindruta I, Balanescu B, Donos C: A vascular safety index for stereotactic targeting of deep brain structures. Stereotact Funct Neurosurg 2012;90(suppl 1):121.
16.
Cardinale F, Cossu M, Castana L, Casaceli G, PSchiariti M, Miserocchi A, Fuschillo D, Moscato A, Caborni C, Arnulfo G, Lo Russo G: Stereoelectroencephalography: surgical methodology, safety, and stereotactic application accuracy in 500 procedures. Neurosurgery 2013;72:353-366.
17.
Balachandran R, Mitchell JE, Dawant BM, Fitzpatrick JM: Accuracy evaluation of microTargeting platforms for deep-brain stimulation using virtual targets. IEEE Trans Biomed Eng 2009;56:37-44.
18.
Cossu M, Cardinale F, Colombo N, Mai R, Nobili L, Sartori I, Lo Russo G: Stereoelectroencephalography in the presurgical evaluation of children with drug-resistant focal epilepsy. J Neurosurg 2005;103:333-343.
19.
Cossu M, Cardinale F, Castana L, Nobili L, Sartori I, Lo Russo G: Stereo-EEG in children. Childs Nerv Syst 2006;22:766-778.
20.
Cossu M, Schiariti M, Francione S, Fuschillo D, Gozzo F, Nobili L, Cardinale F, Castana L, Russo GL: Stereoelectroencephalography in the presurgical evaluation of focal epilepsy in infancy and early childhood. J Neurosurg Pediatr 2012;9:290-300.
21.
Furlanetti LL, Monaco BA, Cordeiro JG, Nikkhah G, Trippel M: Is frame-based surgery in patients under seven years old safe? Experience of Freiburg University from 99 cases. Stereotact Funct Neurosurg 2012;90(suppl 1):180.
22.
Munyon CN, Koubeissi MZ, Syed TU, Luders HO, Miller JP: Accuracy of frame-based stereotactic depth electrode implantation during craniotomy for subdural grid placement. Stereotact Funct Neurosurg 2013;91:399-403.
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