title: Improved Accuracy and Reproducibility Using a Training Protocol for Freehand-SPECT 3D Mapping in Radio-Guided Surgery.
abstract: OBJECTIVE
  Freehand single-photon emission computed tomography (SPECT) (fh-SPECT) for optical tracked 3-dimensional radioactivity mapping raises popularity for sentinel node biopsy and other radio-guided procedures. However, the device seems to be complex, requiring both training and a standardized scan protocol. Therefore, the aim of this study was to compare handling reproducibility between novice and expert users; subsequently, using additional scans, we evaluated a standardized scan protocol to be tested in novice users after receiving training.
  
  
  METHODS
  Three groups (untrained novices, experts, and trained novices), each one composed of 5 fh-SPECT users, were given the same short introduction and the assignment to perform 3 fh-SPECT scans with the same time per scan. For the scans, a reproducible phantom with an iodine-125 point source was used. Furthermore, we performed probe-trajectory evaluation including pattern, speed, and length of scans based on recorded videos and digital target tracking.
  
  
  RESULTS
  The training period encompasses 30 minutes per novice user. The mean error in 3 directions based on 45 measurements was 7.4 mm for untrained novices and 3.2 mm for expert users. The trained novice group had a mean error of 2.9 mm (a significant 61% reduction), comparable to the expert group. The reproducibility values, expressed in SD, were 4.1 mm for the untrained novice group, 1.3 mm for the expert group, and 1.1 mm for the trained novices (73% improvement). The standardized scan protocol was demonstrated by means of trajectory evaluation, a scan path better systematized.
  
  
  CONCLUSIONS
  Scanning with fh-SPECT for radio-guided surgery requires a specific training period to increase handling and reproducibility of 3-dimensional imaging, and to enhance its accuracy in the operating room.
authors.affiliation: From the Department of Nuclear Medicine, The Netherlands Cancer Institute, Antoni van Leeuwenhoek Hospital, Amsterdam, The Netherlands.
authors.forename: Bas
authors.initials: B
authors.lastname: Pouw
authors.forename: Linda J
authors.initials: LJ
authors.lastname: de Wit-van der Veen
authors.forename: Marcel P M
authors.initials: MP
authors.lastname: Stokkel
authors.forename: Renato A
authors.initials: RA
authors.lastname: Valdés Olmos
mesh_terms: D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D017410:Practice Guidelines as Topic; D015203:Reproducibility of Results; D025321:Surgery, Computer-Assisted / Q000379:methods*; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*