title: Dual-phase F-18 FDG PET-CT in staging and lymphoscintigraphy for detection of sentinel lymph nodes in oral cavity cancers.
abstract: OBJECTIVE
  Our objective was to evaluate the diagnostic role of dual-phase fluor-18 fluorodeoxyglucose (F-18 FDG) positron emission tomography-computed tomography (PET-CT) and planar lymphoscintigraphy in patients with oral cavity cancer (OCC). We also investigated the combined impact of F-18 FDG PET-CT and sentinel lymph node biopsy (SLNB) in decision making for patients with OCC.
  
  
  METHODS
  Sixteen patients (4 female, 12 male; age range, 29-81 years) were included in this prospective study. F-18 FDG PET-CT [1 (early) and 2 h (delayed) after injection] and planar lymphoscintigraphy (2h before the surgery) were performed for all the patients before surgery. The sensitivity, specificity, and negative and positive predictive values in F-18 FDG PET-CT for the early and the delayed scans and tumor/liver uptake (T/L) in the lymph nodes were calculated. Receiver operating characteristic curves were obtained for standardized uptake value (SUV)max and T/L.
  
  
  RESULTS
  Histopathological evaluations revealed that 5 patients had metastatic lymph nodes (pN+) whereas 11 patients had benign lymph nodes (pN-). Out of 43 lymph nodes visualized as cN(+) in F-18 FDG PET-CT, 14 were pathologically positive for malignancy, whereas 29 were pathologically benign. There was no statistical difference between the N(+) and N(-) patients in terms of age, depth of primary tumor, and the number of mitoses. However, there was a significant difference between the N(+) and N(-) patients (P=.011) in terms of early and delayed F-18 FDG uptake of primary tumors. There was a statistically significant difference in the value of SUVmax between the early and the delayed scans for the malignant lymph nodes (P=.00).
  
  
  CONCLUSIONS
  This study indicates that F-18 FDG PET-CT is a reliable method for the correct evaluation of primary tumor and N staging in OCCs. Delayed phase of F-18 FDG imaging may increase primary lesion detectability due to higher FDG uptake in primary tumors compared to the early phase of imaging. F-18 FDG PET-CT might demonstrate skip metastasis in lymph nodes which can be missed with SLNB. Although SUV values increased in the delayed phase of F-18 PET-CT imaging in detecting lymph node metastases, the specificity and positive predictive value did not increase.
authors.affiliation: Yüzüncü Yıl University, School of Medicine, Department of Nuclear Medicine, Van, Turkey.
authors.forename: Erdem
authors.initials: E
authors.lastname: Sürücü
authors.affiliation: Dokuz Eylül University, School of Medicine, Department of Nuclear Medicine, Izmir, Turkey.
authors.forename: Berna Degirmenci
authors.initials: BD
authors.lastname: Polack
authors.affiliation: Yüzüncü Yıl University, School of Medicine, Department of Nuclear Medicine, Van, Turkey. Electronic address: dryusufdemir@gmail.com.
authors.forename: Yusuf
authors.initials: Y
authors.lastname: Demir
authors.affiliation: Dokuz Eylül University, School of Medicine, Department of Ear, Eose, Throat and Head & Neck Surgery, Izmir, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Durmuşoğlu
authors.affiliation: Dokuz Eylül University, School of Medicine, Department of Pathology, Izmir, Turkey.
authors.forename: Sümeyye
authors.initials: S
authors.lastname: Ekmekçi
authors.affiliation: Dokuz Eylül University, School of Medicine, Department of Pathology, Izmir, Turkey.
authors.forename: Sülen
authors.initials: S
authors.lastname: Sarıoğlu
authors.affiliation: Dokuz Eylül University, School of Medicine, Department of Radiology, Izmir, Turkey.
authors.forename: Ahmet Orhan
authors.initials: AO
authors.lastname: Çelik
authors.affiliation: Dokuz Eylül University, School of Medicine, Department of Radiology, Izmir, Turkey.
authors.forename: Emel
authors.initials: E
authors.lastname: Ada
authors.affiliation: Dokuz Eylül University, School of Medicine, Department of Ear, Eose, Throat and Head & Neck Surgery, Izmir, Turkey.
authors.forename: Ahmet Ömer
authors.initials: AÖ
authors.lastname: İkiz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging; D008207:Lymphatic Metastasis; D061305:Lymphoscintigraphy; D008297:Male; D008875:Middle Aged; D009055:Mouth / Q000000981:diagnostic imaging / Q000473:pathology; D009062:Mouth Neoplasms / Q000175:diagnosis* / Q000473:pathology; D064847:Multimodal Imaging; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D011446:Prospective Studies; D012372:ROC Curve; D012680:Sensitivity and Specificity; D021701:Sentinel Lymph Node Biopsy; D014057:Tomography, X-Ray Computed
chemical_list: D019788:Fluorodeoxyglucose F18
keywords: Dual phase; F-18 FDG PET–CT; Oral cavity cancers; Planar lymphoscintigraphy