title: Fixation, registration, and image-guided navigation using a thermoplastic facial mask in electromagnetic navigation-guided radiofrequency thermocoagulation.
abstract: OBJECTIVE
  For fixation, registration, and image-guided navigation, the aim of this study was to evaluate a thermoplastic facial mask with plastic markers in achieving frameless stereotactic radiofrequency thermocoagulation (RFT).
  
  
  METHODS
  A thermoplastic facial mask was remolded according to each subject's face. Six markers were placed on the surface and 6 inside. Series of 1.25-mm- and 2.5-mm-slice computerized tomography (CT) scans were made to provide radiologic data. During the phantom study, each plastic sphere inside was selected in turn as the target for frameless stereotaxy. The clinical Hartel puncture of the foramen ovale (FO) was imitated using an electromagnetic navigation system. Navigation-guided RFT was tried in 3 patients.
  
  
  RESULTS
  The mean location error was 1.29 mm (SD ± 0.39 mm). No significant difference (P > .05) was proven between 1.25-mm and 2.5-mm CT slice acquisition for the image datasets used. The FO punctures in clinical trials were successful and confirmed by CT.
  
  
  CONCLUSIONS
  Registration and fixation via a fiducial marker-based thermoplastic facial mask is accurate and feasible for use in navigation-guided RFT.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai Key Laboratory of Stomatology, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Min-jie
authors.initials: MJ
authors.lastname: Chen
authors.forename: Li-xu
authors.initials: LX
authors.lastname: Gu
authors.forename: Wei-jie
authors.initials: WJ
authors.lastname: Zhang
authors.forename: Chi
authors.initials: C
authors.lastname: Yang
authors.forename: Jing
authors.initials: J
authors.lastname: Zhao
authors.forename: Zi-yang
authors.initials: ZY
authors.lastname: Shao
authors.forename: Bao-li
authors.initials: BL
authors.lastname: Wang
mesh_terms: D017115:Catheter Ablation / Q000295:instrumentation* / Q000379:methods; D055590:Electromagnetic Phenomena; D005260:Female; D057918:Fiducial Markers; D006801:Humans; D008297:Male; D008397:Masks; D008875:Middle Aged; D038361:Neuronavigation / Q000295:instrumentation* / Q000379:methods; D056888:Patient Positioning; D019047:Phantoms, Imaging; D010969:Plastics; D013100:Sphenoid Bone / Q000601:surgery; D036542:Tomography, Spiral Computed; D014277:Trigeminal Neuralgia / Q000601:surgery*
chemical_list: D010969:Plastics