title: Metabolic activity measured by F-18 FDG PET in natural killer-cell lymphoma compared to aggressive B- and T-cell lymphomas.
abstract: OBJECTIVE
  We aim to compare the metabolic activity by F-18 fluorodeoxyglucose (FDG) uptake across the various histologic subtypes of non-Hodgkin lymphoma (NHL) in a single center, with particular interest in the natural killer (NK)-cell lymphoma subtype for which literature is scarce because of the rarity of these lymphomas in Western populations.
  
  
  METHODS
  We retrospectively evaluated the FDG-avidity of pretreatment positron emission tomography-computed tomography scans of 117 consecutive NHL patients by measuring the lesion with the highest maximum standardized uptake value (SUV(max)) in each patient. Mean SUV(max) of 4 major groups of NHL; aggressive B-cell (n = 63), indolent B-cell (n = 31), NK-cell (n = 14) and aggressive T-cell lymphoma (n = 9), was compared using one-way analysis of variance. P value <0.05 was considered statistically significant.
  
  
  RESULTS
  SUV(max) (mean +/- standard deviation) of NK-cell lymphoma (9.2 +/- 4.5) was significantly lower than aggressive B-cell lymphoma (14.1 +/- 6.4) (P = 0.013), similar to aggressive T-cell lymphoma (7.6 +/- 3.9) and significantly higher than that of indolent B-cell lymphoma (5.3 +/- 3.1) (P = 0.039).
  
  
  CONCLUSIONS
  The metabolic phenotype, characterized by FDG uptake of the various NHL subtypes is described. Although NK-cell lymphomas demonstrate high metabolic activity, SUV(max) is significantly lower than its aggressive B-cell counterparts. This may reflect the large amount of coagulative necrosis and inflammatory component of the tumor, and the relatively slower tumor growth rate compared with aggressive B-cell lymphomas.
authors.affiliation: Department of Diagnostic Radiology, Queen Mary Hospital, The University of Hong Kong, Hong Kong S.A.R., China.
authors.forename: Winnie K S
authors.initials: WK
authors.lastname: Chan
authors.forename: Wing-Yan
authors.initials: WY
authors.lastname: Au
authors.forename: Ching-Yee O
authors.initials: CY
authors.lastname: Wong
authors.forename: Raymond
authors.initials: R
authors.lastname: Liang
authors.forename: Anskar Y H
authors.initials: AY
authors.lastname: Leung
authors.forename: Yok-Lam
authors.initials: YL
authors.lastname: Kwong
authors.forename: Pek-Lan
authors.initials: PL
authors.lastname: Khong
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007694:Killer Cells, Natural / Q000378:metabolism*; D016393:Lymphoma, B-Cell / Q000000981:diagnostic imaging* / Q000378:metabolism* / Q000473:pathology; D016399:Lymphoma, T-Cell / Q000000981:diagnostic imaging* / Q000378:metabolism* / Q000473:pathology; D008875:Middle Aged; D049268:Positron-Emission Tomography; D012189:Retrospective Studies; D055815:Young Adult
chemical_list: D019788:Fluorodeoxyglucose F18