title: Prognosis estimation under the light of metabolic tumor parameters on initial FDG-PET/CT in patients with primary extranodal lymphoma.
abstract: BACKGROUND
  Non-Hodgkin's lymphomas arising from the tissues other than primary lymphatic organs are named primary extranodal lymphoma. Most of the studies evaluated metabolic tumor parameters in different organs and histopathologic variants of this disease generally for treatment response. We aimed to evaluate the prognostic value of metabolic tumor parameters derived from initial FDG-PET/CT in patients with a medley of primary extranodal lymphoma in this study.
  
  
  METHODS
  There were 67 patients with primary extranodal lymphoma for whom FDG-PET/CT was requested for primary staging. Quantitative PET/CT parameters: maximum standardized uptake value (SUVmax), average standardized uptake value (SUVmean), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were used to estimate disease-free survival and overall survival.
  
  
  RESULTS
  SUVmean, MTV and TLG were found statistically significant after multivariate analysis. SUVmean remained significant after ROC curve analysis. Sensitivity and specificity were calculated as 88% and 64%, respectively, when the cut-off value of SUVmean was chosen as 5.15. After the investigation of primary presentation sites and histo-pathological variants according to recurrence, there is no difference amongst the variants. Primary site of extranodal lymphomas however, is statistically important (p = 0.014). Testis and central nervous system lymphomas have higher recurrence rate (62.5%, 73%, respectively).
  
  
  CONCLUSIONS
  High SUVmean, MTV and TLG values obtained from primary staging FDG-PET/CT are potential risk factors for both disease-free survival and overall survival in primary extranodal lymphoma. SUVmean is the most significant one amongst them for estimating recurrence/metastasis.
authors.affiliation: Department of Nuclear Medicine, Gulhane Military Medical Academy (GATA), Ankara, Turkey.
authors.forename: Kursat
authors.initials: K
authors.lastname: Okuyucu
authors.affiliation: Department of Medical Oncology, Gulhane Military Medical Academy (GATA), Ankara, Turkey.
authors.forename: Sukru
authors.initials: S
authors.lastname: Ozaydın
authors.affiliation: Department of Nuclear Medicine, Gulhane Military Medical Academy (GATA), Ankara, Turkey.
authors.forename: Engin
authors.initials: E
authors.lastname: Alagoz
authors.affiliation: Department of Haematology, Gulhane Military Medical Academy (GATA), Ankara, Turkey.
authors.forename: Gokhan
authors.initials: G
authors.lastname: Ozgur
authors.affiliation: Department of Nuclear Medicine, Gulhane Military Medical Academy (GATA), Ankara, Turkey.
authors.forename: Semra
authors.initials: S
authors.lastname: Ince
authors.affiliation: Department of Public Health, Gulhane Military Medical Academy (GATA), Ankara, Turkey.
authors.forename: Fahrettin Guven
authors.initials: FG
authors.lastname: Oysul
authors.affiliation: Department of Nuclear Medicine, Ataturk Chest Diseases and Thoracic Surgery Training and Research Hospital, Kecioren, Ankara, Turkey.
authors.forename: Ozlem
authors.initials: O
authors.lastname: Ozmen
authors.affiliation: Department of Nuclear Medicine, Hacettepe University, Ankara, Turkey.
authors.forename: Murat
authors.initials: M
authors.lastname: Tuncel
authors.affiliation: Department of Medical Oncology, Gulhane Military Medical Academy (GATA), Ankara, Turkey.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Ozturk
authors.affiliation: Department of Nuclear Medicine, Gulhane Military Medical Academy (GATA), Ankara, Turkey.
authors.forename: Nuri
authors.initials: N
authors.lastname: Arslan
keywords: 18-fluorodeoxyglucose positron emission tomography/computed tomography; metabolic tumor parameters; primary extranodal lymphoma