title: Blurring the boundaries between frame-based and frameless stereotaxy: feasibility study for brain biopsies performed with the use of a head-mounted robot.
abstract: OBJECTIVE
  Frame-based stereotactic interventions are considered the gold standard for brain biopsies, but they have limitations with regard to flexibility and patient comfort because of the bulky head ring attached to the patient. Frameless image guidance systems that use scalp fiducial markers offer more flexibility and patient comfort but provide less stability and accuracy during drilling and biopsy needle positioning. Head-mounted robot-guided biopsies could provide the advantages of these 2 techniques without the downsides. The goal of this study was to evaluate the feasibility and safety of a robotic guidance device, affixed to the patient's skull through a small mounting platform, for use in brain biopsy procedures.
  
  
  METHODS
  This was a retrospective study of 37 consecutive patients who presented with supratentorial lesions and underwent brain biopsy procedures in which a surgical guidance robot was used to determine clinical outcomes and technical procedural operability.
  
  
  RESULTS
  The portable head-mounted device was well tolerated by the patients and enabled stable drilling and needle positioning during surgery. Flexible adjustments of predefined paths and selection of new trajectories were successfully performed intraoperatively without the need for manual settings and fixations. The patients experienced no permanent deficits or infections after surgery.
  
  
  CONCLUSIONS
  The head-mounted robot-guided approach presented here combines the stability of a bone-mounted set-up with the flexibility and tolerability of frameless systems. By reducing human interference (i.e., manual parameter settings, calibrations, and adjustments), this technology might be particularly useful in neurosurgical interventions that necessitate multiple trajectories.
authors.affiliation: Division of Functional and Restorative Neurosurgery, Department of Neurosurgery, Eberhard Karls University, Tuebingen; and.
authors.forename: Florian
authors.initials: F
authors.lastname: Grimm
authors.affiliation: Division of Functional and Restorative Neurosurgery, Department of Neurosurgery, Eberhard Karls University, Tuebingen; and.
authors.forename: Georgios
authors.initials: G
authors.lastname: Naros
authors.affiliation: Department of Neurosurgery, Johannes Gutenberg University, Mainz, Germany.
authors.forename: Angelika
authors.initials: A
authors.lastname: Gutenberg
authors.affiliation: Department of Neurosurgery, Johannes Gutenberg University, Mainz, Germany.
authors.forename: Naureen
authors.initials: N
authors.lastname: Keric
authors.affiliation: Department of Neurosurgery, Johannes Gutenberg University, Mainz, Germany.
authors.forename: Alf
authors.initials: A
authors.lastname: Giese
authors.affiliation: Division of Functional and Restorative Neurosurgery, Department of Neurosurgery, Eberhard Karls University, Tuebingen; and.
authors.forename: Alireza
authors.initials: A
authors.lastname: Gharabaghi
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy / Q000379:methods; D001921:Brain / Q000473:pathology / Q000601:surgery*; D001927:Brain Diseases / Q000473:pathology / Q000601:surgery*; D001932:Brain Neoplasms / Q000473:pathology / Q000601:surgery; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D038361:Neuronavigation / Q000379:methods*; D012189:Retrospective Studies; D012371:Robotics; D013238:Stereotaxic Techniques; D025321:Surgery, Computer-Assisted / Q000379:methods*; D055815:Young Adult
keywords: diagnostic and operative techniques; frame-based brain biopsy; frameless brain biopsy; neuronavigation; oncology; robotics; stereotaxy; tumor