title: First Experiences with Navigated Radio-Guided Surgery Using Freehand SPECT.
abstract: BACKGROUND
  Sentinel lymph node biopsy (SLNB) in melanoma using one-dimensional gamma probes is a standard of care worldwide. Reports on the performance are claimed by most groups to successfully detect the SLNs during the surgical procedure in almost 100% of the patients. In clinical practice, however, several issues remain which are usually not addressed: the difficulty of intraoperative detection of deeply located nodes, SLN detection in obese patients or in the groin and the impossibility to make a scan of the entire wound after SLN resection to avoid false negative testing for eventually remaining SLNs.
  
  
  METHODS
  The concept behind freehand SPECT is to combine a gamma probe as used for conventional radio-guided surgery with a tracking system as used in neurosurgical navigation. From this combination and a proper algorithm framework the 3D reconstruction of radioactivity distributions and displaying these intraoperatively is possible.
  
  
  CONCLUSIONS
  In summary, the feasibility of freehand SPECT could be shown and provides an image-guided SLNB and a truly minimally invasive and optimized surgical procedure.
authors.affiliation: Department of Surgery, Technische Universität München, and, Munich, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Rieger
authors.forename: J
authors.initials: J
authors.lastname: Saeckl
authors.forename: B
authors.initials: B
authors.lastname: Belloni
authors.forename: R
authors.initials: R
authors.lastname: Hein
authors.forename: A
authors.initials: A
authors.lastname: Okur
authors.forename: K
authors.initials: K
authors.lastname: Scheidhauer
authors.forename: T
authors.initials: T
authors.lastname: Wendler
authors.forename: J
authors.initials: J
authors.lastname: Traub
authors.forename: H
authors.initials: H
authors.lastname: Friess
authors.forename: M E
authors.initials: ME
authors.lastname: Martignoni