title: 18F-FDG uptake on PET in primary mediastinal non-thymic neoplasm: a clinicopathological study.
abstract: BACKGROUND
  The usefulness of 2-[(18)F]-fluoro-2-deoxy-D-glucose ((18)F-FDG) positron emission tomography (PET) has been investigated in thymic epithelial tumors. However, little is known about PET imaging of (18)F-FDG in primary non-thymic mediastinal neoplasms. The aim of this study is to explore the clinicopathological significance of (18)F-FDG PET in primary mediastinal (non-thymic) neoplasms.
  
  
  METHODS
  Twenty-one patients with mediastinal neoplasms who underwent (18)F-FDG PET before treatment were included in this study. Tumor sections were stained by immunohistochemistry for glucose transporter 1 (Glut1); glucose transporter 3 (Glut3); hypoxia-inducible factor-1 alpha (HIF-1α); hexokinase I; vascular endothelial growth factor (VEGF); microvessels (CD34); epidermal growth factor receptor (EGFR); Akt/mTOR signaling pathway (p-Akt and p-mTOR); cell cycle control (p53).
  
  
  RESULTS
  Seventeen of 21 patients were imaged on PET system using (18)F-FDG, but 4 patients with a histology of cyst showed nothing abnormal in PET scans. The histology of the resected tumors was as follows: 6 schwannoma, 3 teratoma, 4 cyst, 3 sarcoma, 1 undifferentiated carcinoma, 1 seminoma, 1 mediastinal goiter, 1 ganglioneuroma, and 1 Hodgkin lymphoma. (18)F-FDG uptake was significantly correlated with Glut1, HIF-1α, EGFR, p-Akt and p-S6K. These biomarkers were highly expressed in schwannoma, teratoma and high grade malignancies, whereas all patients with cyst and ganglioneuroma had no positive expression of these biomarkers. High uptake of (18)F-FDG was significant associated with Glut1, VEGF, EGFR, p-Akt, p-S6K and tumor maximal size.
  
  
  CONCLUSIONS
  The amount of (18)F-FDG uptake in primary mediastinal non-thymic neoplasms is determined by the presence of glucose metabolism (Glut1), hypoxia (HIF-1α) and upstream components of HIF-1α (EGFR, p-Akt and p-S6K).
authors: Division of Thoracic Oncology, Shizuoka Cancer Center, 1007 Shimonagakubo Nagaizumi-cho, Sunto-gun, Shizuoka 411-8777, Japan. kkaira1970@yahoo.co.jp
authors: Kyoichi
authors: K
authors: Kaira
authors: Masato
authors: M
authors: Abe
authors: Kazuo
authors: K
authors: Nakagawa
authors: Yasuhisa
authors: Y
authors: Ohde
authors: Takehiro
authors: T
authors: Okumura
authors: Toshiaki
authors: T
authors: Takahashi
authors: Haruyasu
authors: H
authors: Murakami
authors: Takehito
authors: T
authors: Shukuya
authors: Hirotsugu
authors: H
authors: Kenmotsu
authors: Tateaki
authors: T
authors: Naito
authors: Isamu
authors: I
authors: Hayashi
authors: Noboru
authors: N
authors: Oriuchi
authors: Masahiro
authors: M
authors: Endo
authors: Haruhiko
authors: H
authors: Kondo
authors: Takashi
authors: T
authors: Nakajima
authors: Nobuyuki
authors: N
authors: Yamamoto
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D006801:Humans; D008297:Male; D008479:Mediastinal Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism*; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013953:Thymus Neoplasms / Q000000981:diagnostic imaging / Q000378:metabolism; D014018:Tissue Distribution; D055815:Young Adult
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18