title: Effect of time-of-flight technique on the diagnostic performance of 18F-FDG PET/CT for assessment of lymph node metastases in head and neck squamous cell carcinoma.
abstract: Precise assessment of lymph node metastases is critical to the treatment outcome and overall survival of patients with head and neck squamous cell carcinoma (HNSCC). The purpose of this study was to investigate the effect of time-of-flight (TOF) technique on the diagnostic performance of (18)F-FDG PET/CT for assessment of lymph node metastases in HNSCC patients.
  
  
  METHODS
  In 39 patients with an initial diagnosis of HNSCC, preoperative staging (18)F-FDG PET/CT was performed to assess lymph node metastases before surgery and histologic verification. Potential lymph node metastases were evaluated and documented separately for the right and left neck in accordance with the head and neck lymph node level classification. Two experienced readers measured lesion volume and uptake for every PET-positive lymph node. Sensitivity, specificity, image quality, and the PET characterization of the lesion (benign or malignant) were compared between different reconstruction methods (TOF PET and standard high-definition PET) and matrices for both readers.
  
  
  RESULTS
  TOF PET significantly increased the maximal standardized uptake value (SUVmax) but had no significant effect on lesion volume. However, a higher SUVmax did not result in a significant increase in small-lesion detection. Sensitivity and image quality were slightly improved with TOF PET but not significantly so. Matrix, on the other hand, had a significant effect on detected lesion numbers, sensitivity, and image quality.
  
  
  CONCLUSIONS
  For preoperative assessment of lymph node metastases in HNSCC, (18)F-FDG PET/CT using TOF technique increases SUVmax in lesions and improves image quality but has no significant impact on small-lesion detectability.
authors: Institute of Clinical Radiology and Nuclear Medicine, University Hospital Mannheim, Medical Faculty Mannheim of the University of Heidelberg, Heidelberg, Germany Department of Nuclear Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China julie850310@gmail.com.
authors: Chun-Yan
authors: CY
authors: Li
authors: Institute of Clinical Radiology and Nuclear Medicine, University Hospital Mannheim, Medical Faculty Mannheim of the University of Heidelberg, Heidelberg, Germany.
authors: Sarah
authors: S
authors: Klohr
authors: Department of Otorhinolaryngology and Head and Neck Surgery, University Hospital Mannheim, Medical Faculty Mannheim of the University of Heidelberg, Heidelberg, Germany; and.
authors: Haneen
authors: H
authors: Sadick
authors: Department of Biostatistics, University Hospital Mannheim, Medical Faculty Mannheim of the University of Heidelberg, Heidelberg, Germany.
authors: Christel
authors: C
authors: Weiss
authors: Department of Otorhinolaryngology and Head and Neck Surgery, University Hospital Mannheim, Medical Faculty Mannheim of the University of Heidelberg, Heidelberg, Germany; and.
authors: Karl
authors: K
authors: Hoermann
authors: Institute of Clinical Radiology and Nuclear Medicine, University Hospital Mannheim, Medical Faculty Mannheim of the University of Heidelberg, Heidelberg, Germany.
authors: Stefan O
authors: SO
authors: Schoenberg
authors: Institute of Clinical Radiology and Nuclear Medicine, University Hospital Mannheim, Medical Faculty Mannheim of the University of Heidelberg, Heidelberg, Germany.
authors: Maliha
authors: M
authors: Sadick
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis* / Q000473:pathology; D005260:Female; D019788:Fluorodeoxyglucose F18; D006258:Head and Neck Neoplasms / Q000175:diagnosis* / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D000077195:Squamous Cell Carcinoma of Head and Neck; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: 18F-FDG PET/CT; head and neck squamous cell carcinoma; lymph node metastases; time-of-flight