title: Efficacy of 18-FDG PET-CT dual-phase scanning for detection of lymph node metastasis in gynecological cancer.
abstract: OBJECTIVE
  This study investigated whether dual-phase scanning (DPS) with 18-fludeoxyglucose positron emission tomography -computed tomography (FDG PET-CT) improves diagnosis of lymph node metastasis (LNM) in gynecologic malignancies, compared to mono-phase scanning (MPS).
  
  
  METHODS
  The study included 139 patients who underwent PET-CT followed by systemic lymph node dissection. PET-CT scans were obtained twice. The maximum standardized uptake value (SUVmax) was measured and the retention index (RI) was calculated as the % change from the early to the delayed scan. The optimal threshold of RI was determined using a receiver operating characteristic (ROC) curve. Diagnostic efficacies were calculated for MPS and DPS using pathological results.
  
  
  RESULTS
  In total, 1,879 regions were dissected. The optimal RI was 9%. The sensitivity, specificity and accuracy were 35.8%, 99.0% and 96.8% for MPS and 26.9%, 99.6% and 97.0% for DPS, respectively. Specificity was significantly improved by DPS and accuracy was also improved, but not significantly.
  
  
  CONCLUSIONS
  DPS had an unsatisfactory impact on the diagnostic efficacy for LNM.
authors: Department of Obstetrics and Gynecology, School of Medicine, Keio University, Tokyo, Japan.
authors: Yuya
authors: Y
authors: Nogami
authors: Department of Obstetrics and Gynecology, School of Medicine, Keio University, Tokyo, Japan kbanno@z7.keio.jp.
authors: Kouji
authors: K
authors: Banno
authors: Department of Obstetrics and Gynecology, School of Medicine, Keio University, Tokyo, Japan.
authors: Haruko
authors: H
authors: Irie
authors: Department of Obstetrics and Gynecology, School of Medicine, Keio University, Tokyo, Japan.
authors: Miho
authors: M
authors: Iida
authors: Department of Pathology, School of Medicine, Keio University, Tokyo, Japan.
authors: Yohei
authors: Y
authors: Masugi
authors: Department of Radiology, School of Medicine, Keio University, Tokyo, Japan.
authors: Koji
authors: K
authors: Murakami
authors: Department of Obstetrics and Gynecology, School of Medicine, Keio University, Tokyo, Japan.
authors: Daisuke
authors: D
authors: Aoki
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D019788:Fluorodeoxyglucose F18; D005833:Genital Neoplasms, Female / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008207:Lymphatic Metastasis / Q000175:diagnosis* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography / Q000379:methods*; D014057:Tomography, X-Ray Computed
chemical_list: D019788:Fluorodeoxyglucose F18
keywords: Positron emission tomography; clinical oncology; diagnostic imaging; gynecology; lymphatic metastasis