title: Multimodal image registration for localization of sentinel nodes in head and neck squamous cell carcinoma.
abstract: OBJECTIVE
  The aim of this clinical study was to propose a new method of preoperative 3-dimensional localization of the neck sentinel node in clinically and radiographically N0 squamous cell carcinoma of the oral cavity.
  
  
  METHODS
  This prospective study was carried out between August 2002 and August 2003. Ten patients with staged oral squamous cell cancer underwent this method of preoperative localization of the sentinel lymph node. At the present time, lymphoscintigraphy is recognized as the investigation of choice for the preoperative detection of sentinel nodes. Although we found it to be highly sensitive (100% in our study), it does not allow precise localization of the sentinel node in the anatomic context of the neck. To overcome this drawback, we used multimodal image registration applied to the cervical region in association with the imaging modalities of scintigraphy (single-photon emission computed tomography [SPECT] and gamma transmission) and computed tomography (CT). SPECT and gamma transmission (barium-133 sources) were carried out with a triple-head Philips-Marconi camera (Philips Medical System, Cleveland, OH), and CT was carried out with a General Electric console (GE Medical Systems, Milwaukee, WI). Gamma transmission was used to place the SPECT images in a reference cervical anatomic context (CT images). Registration involved the use of a manual method based on definition of homologous volume structures.
  
  
  RESULTS
  Preoperative image registration effectively localized the cervical sentinel node in 9 of the 10 patients, enabling a guided surgical approach in 90% of cases. The sentinel node was localized and resected using a hand-held gamma probe.
  
  
  CONCLUSIONS
  This original study adapts a new tool (multimodal image registration) to obtain precise preoperative localization of the cervical sentinel node in N0 oral squamous cell carcinoma. We confirmed the feasibility of this method in this indication. Although this method is a novel one, we believe that it will become extremely useful once a consensus has been reached on exclusive excision of the cervical sentinel node in oral cancers, as is the case for melanoma or breast cancer.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Purpan Hospital, Toulouse, France.
authors.forename: Raphaël
authors.initials: R
authors.lastname: Lopez
authors.forename: Pierre
authors.initials: P
authors.lastname: Payoux
authors.forename: Pierre
authors.initials: P
authors.lastname: Gantet
authors.forename: Jean Paul
authors.initials: JP
authors.lastname: Esquerré
authors.forename: Franck
authors.initials: F
authors.lastname: Boutault
authors.forename: Jean Roch
authors.initials: JR
authors.lastname: Paoli
mesh_terms: D000328:Adult; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000556:secondary* / Q000601:surgery; D005260:Female; D006258:Head and Neck Neoplasms / Q000175:diagnosis / Q000601:surgery*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000175:diagnosis / Q000601:surgery; D011300:Preoperative Care; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy / Q000379:methods; D012878:Skin Neoplasms / Q000175:diagnosis / Q000601:surgery; D015899:Tomography, Emission-Computed, Single-Photon; D014057:Tomography, X-Ray Computed