title: Dexamethasone Suppression FDG PET/CT for Differentiating between True- and False-Positive Pulmonary and Mediastinal Lymph Node Metastases in Non-Small Cell Lung Cancer: A Pilot Study of FDG PET/CT after Oral Administration of Dexamethasone.
abstract: OBJECTIVE
  To examine whether dexamethasone suppression can reduce fluorine 18 fluorodeoxyglucose (FDG) uptake in false-positive (FP) findings in pulmonary and mediastinal lymph nodes in non-small cell lung cancer (NSCLC).
  
  
  METHODS
  Institutional ethics review board approved this prospective study with written informed consent. The study population was composed of 17 patients with NSCLC who underwent both baseline and dexamethasone suppression (24 hours after oral administration of 8 mg dexamethasone) FDG positron emission tomography/computed tomography and surgery. FDG uptake was evaluated by using a five-point visual scoring system (negative findings, score of 0-1; positive findings, score of 2-4) and maximum standardized uptake value (SUVmax). The Mann-Whitney U, Wilcoxon signed-rank, Kruskal-Wallis, or Spearman rank correlation tests were used as necessary for statistical evaluations.
  
  
  RESULTS
  In 17 primary lesions, no significant difference was noted in visual score between baseline (mean, 3.4 ± 1.2) and dexamethasone suppression scans (mean, 3.3 ± 1.2; P = .16), although SUVmax was significantly lower on dexamethasone suppression scans (mean, 7.1 ± 5.2) than on baseline scans (mean, 8.6 ± 6.6; P = .005). In eight nodes with true-positive (TP) findings, there were no significant differences in visual score (mean for both, 3.8 ± 0.5) and SUVmax (mean, 5.3 ± 2.3 vs 5.5 ± 2.5, respectively; P = .81) between baseline and dexamethasone suppression scans. In 19 nodes with FP findings at baseline, dexamethasone suppression resulted in significantly lowered visual score (mean, 3.4 ± 0.6 vs 2.4 ± 0.8, respectively; P < .001) and SUVmax (mean, 3.5 ± 0.8 vs 2.7 ± 0.7, respectively; P < .001), and four nodes with FP findings were rated as true-negative findings on dexamethasone suppression scans, which resulted in a significant difference in SUVmax between nodal lesions with TP and FP findings (P = .014).
  
  
  CONCLUSIONS
  Oral dexamethasone has the potential to reduce FDG uptake in pulmonary and mediastinal nodes with FP findings in NSCLC.
authors.affiliation: From the Departments of Radiology (Masatoyo Nakajo, M.J., Y. Nakabeppu, T.Y.), Human Pathology (M.H.), and Thoracic Surgery (Y. Nakamura, M.S.), Kagoshima University, Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8544, Japan; Department of Radiology, Nanpuh Hospital, Kagoshima, Japan (Masayuki Nakajo); and Department of Radiology, Kagoshima City Hospital, Kagoshima, Japan (H.N.).
authors.forename: Masatoyo
authors.initials: M
authors.lastname: Nakajo
authors.affiliation: From the Departments of Radiology (Masatoyo Nakajo, M.J., Y. Nakabeppu, T.Y.), Human Pathology (M.H.), and Thoracic Surgery (Y. Nakamura, M.S.), Kagoshima University, Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8544, Japan; Department of Radiology, Nanpuh Hospital, Kagoshima, Japan (Masayuki Nakajo); and Department of Radiology, Kagoshima City Hospital, Kagoshima, Japan (H.N.).
authors.forename: Masayuki
authors.initials: M
authors.lastname: Nakajo
authors.affiliation: From the Departments of Radiology (Masatoyo Nakajo, M.J., Y. Nakabeppu, T.Y.), Human Pathology (M.H.), and Thoracic Surgery (Y. Nakamura, M.S.), Kagoshima University, Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8544, Japan; Department of Radiology, Nanpuh Hospital, Kagoshima, Japan (Masayuki Nakajo); and Department of Radiology, Kagoshima City Hospital, Kagoshima, Japan (H.N.).
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Nakayama
authors.affiliation: From the Departments of Radiology (Masatoyo Nakajo, M.J., Y. Nakabeppu, T.Y.), Human Pathology (M.H.), and Thoracic Surgery (Y. Nakamura, M.S.), Kagoshima University, Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8544, Japan; Department of Radiology, Nanpuh Hospital, Kagoshima, Japan (Masayuki Nakajo); and Department of Radiology, Kagoshima City Hospital, Kagoshima, Japan (H.N.).
authors.forename: Megumi
authors.initials: M
authors.lastname: Jinguji
authors.affiliation: From the Departments of Radiology (Masatoyo Nakajo, M.J., Y. Nakabeppu, T.Y.), Human Pathology (M.H.), and Thoracic Surgery (Y. Nakamura, M.S.), Kagoshima University, Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8544, Japan; Department of Radiology, Nanpuh Hospital, Kagoshima, Japan (Masayuki Nakajo); and Department of Radiology, Kagoshima City Hospital, Kagoshima, Japan (H.N.).
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Nakabeppu
authors.affiliation: From the Departments of Radiology (Masatoyo Nakajo, M.J., Y. Nakabeppu, T.Y.), Human Pathology (M.H.), and Thoracic Surgery (Y. Nakamura, M.S.), Kagoshima University, Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8544, Japan; Department of Radiology, Nanpuh Hospital, Kagoshima, Japan (Masayuki Nakajo); and Department of Radiology, Kagoshima City Hospital, Kagoshima, Japan (H.N.).
authors.forename: Michiyo
authors.initials: M
authors.lastname: Higashi
authors.affiliation: From the Departments of Radiology (Masatoyo Nakajo, M.J., Y. Nakabeppu, T.Y.), Human Pathology (M.H.), and Thoracic Surgery (Y. Nakamura, M.S.), Kagoshima University, Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8544, Japan; Department of Radiology, Nanpuh Hospital, Kagoshima, Japan (Masayuki Nakajo); and Department of Radiology, Kagoshima City Hospital, Kagoshima, Japan (H.N.).
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Nakamura
authors.affiliation: From the Departments of Radiology (Masatoyo Nakajo, M.J., Y. Nakabeppu, T.Y.), Human Pathology (M.H.), and Thoracic Surgery (Y. Nakamura, M.S.), Kagoshima University, Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8544, Japan; Department of Radiology, Nanpuh Hospital, Kagoshima, Japan (Masayuki Nakajo); and Department of Radiology, Kagoshima City Hospital, Kagoshima, Japan (H.N.).
authors.forename: Masami
authors.initials: M
authors.lastname: Sato
authors.affiliation: From the Departments of Radiology (Masatoyo Nakajo, M.J., Y. Nakabeppu, T.Y.), Human Pathology (M.H.), and Thoracic Surgery (Y. Nakamura, M.S.), Kagoshima University, Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8544, Japan; Department of Radiology, Nanpuh Hospital, Kagoshima, Japan (Masayuki Nakajo); and Department of Radiology, Kagoshima City Hospital, Kagoshima, Japan (H.N.).
authors.forename: Takashi
authors.initials: T
authors.lastname: Yoshiura
mesh_terms: D000284:Administration, Oral; D000368:Aged; D000369:Aged, 80 and over; D000972:Antineoplastic Agents, Phytogenic / Q000008:administration & dosage*; D002289:Carcinoma, Non-Small-Cell Lung / Q000473:pathology*; D003907:Dexamethasone / Q000008:administration & dosage*; D003937:Diagnosis, Differential; D005189:False Positive Reactions; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008175:Lung Neoplasms / Q000473:pathology*; D008207:Lymphatic Metastasis / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009367:Neoplasm Staging; D010865:Pilot Projects; D049268:Positron-Emission Tomography / Q000379:methods*; D011446:Prospective Studies; D019275:Radiopharmaceuticals; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D003907:Dexamethasone