title: Is there an additional value of SPECT/CT over planar lymphoscintigraphy for sentinel node mapping in oral/oropharyngeal squamous cell carcinoma?
abstract: BACKGROUND
  Lymphatic mapping for sentinel node biopsy (SNB) has been shown to be crucial for detection of sentinel lymph nodes (SLN). Previous reports suggested a benefit of single photon emission computed tomography with CT (SPECT/CT) over dynamic planar lymphoscintigraphy (LS) alone. The aim was to assess whether there is an additional value of SPECT/CT over LS alone for lymphatic mapping of SLNs in oral/oropharyngeal SCC.
  
  
  METHODS
  A consecutive cohort of 58 patients was evaluated using SNB with additional SPECT/CT to preoperative LS.
  
  
  RESULTS
  In the entire cohort of 58 patients undergoing LS and SPECT/CT, hot spots could be revealed in all but 4 cases. The guidance of the handheld gamma probe was able to reveal 9 additional SLNs within 3 patients not detected by either modality. Lymphoscintigraphy showed full concordance with SPECT/CT in 81% of the cases. SPECT/CT was able to detect additional HS in 11 patients, in 1 case even with additional metastatic disease. The false negative rate for SNB was 6%, and the negative predictive value 98%.
  
  
  CONCLUSIONS
  SPECT/CT has the potential to detect more SLNs, which might harbor occult disease, than LS alone. With regard to the excellent results achieved with LS and the intraoperative use of the gamma probe, SPECT/CT is not indispensable for successful SNB. Both imaging modalities have difficulties in detecting level I sentinel nodes close to the injection site.
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, University Hospital Zurich, Zurich, Switzerland.
authors.forename: Stephan K
authors.initials: SK
authors.lastname: Haerle
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Hany
authors.forename: Klaus
authors.initials: K
authors.lastname: Strobel
authors.forename: Daniel
authors.initials: D
authors.lastname: Sidler
authors.forename: Sandro J
authors.initials: SJ
authors.lastname: Stoeckli
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis / Q000556:secondary / Q000601:surgery; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000175:diagnosis* / Q000601:surgery; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000601:surgery; D009367:Neoplasm Staging; D009959:Oropharyngeal Neoplasms / Q000175:diagnosis* / Q000601:surgery; D011379:Prognosis; D011446:Prospective Studies; D021701:Sentinel Lymph Node Biopsy; D015996:Survival Rate; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome