title: Predicting malignancy grade with PET in non-Hodgkin's lymphoma.
abstract: Our goal was to determine whether PET with 11C-methionine and/or 18FDG could predict malignancy grade in non-Hodgkin's lymphoma (NHL).
  
  
  METHODS
  Twenty-three patients with high-grade, low-grade or transformed low-grade NHL were investigated. Standardized uptake values (SUV), transport rate and mass influx values were calculated both for the whole tumor [mean regions of interest, (ROI)] and for the tumor area with the highest levels of activity, comprising four contiguous pixels within each tumor and designated as a hot spot.
  
  
  RESULTS
  Both 11C-methionine and 18FDG detected all tumors. In addition, 18FDG discriminated between high- and low-grade NHL, whereas 11C-methionine did not. With 18FDG, three transformed low-grade NHLs behaved in an intermediate manner. All quantitative uptake values correlated well with each other for both tracers, except for the mean ROI SUV and transport rate of 11C-methionine. Quantifications of mean ROI uptake and hot spots were strongly correlated.
  
  
  CONCLUSIONS
  The results of this study together with previous findings from other studies indicate that 18FDG but not 11C-methionine can predict malignancy grade in NHL. Further studies with a larger series of patients are needed.
authors.affiliation: Department of Diagnostic Radiology, University of Uppsala, Akademiska Sjukhuset, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Rodriguez
authors.forename: S
authors.initials: S
authors.lastname: Rehn
authors.forename: H
authors.initials: H
authors.lastname: Ahlström
authors.forename: C
authors.initials: C
authors.lastname: Sundström
authors.forename: B
authors.initials: B
authors.lastname: Glimelius
mesh_terms: D000328:Adult; D000368:Aged; D003847:Deoxyglucose / Q000031:analogs & derivatives*; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008228:Lymphoma, Non-Hodgkin / Q000000981:diagnostic imaging* / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008715:Methionine; D008875:Middle Aged; D011237:Predictive Value of Tests; D014055:Tomography, Emission-Computed
chemical_list: D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; C086242:carbon-11 methionine; D003847:Deoxyglucose; D008715:Methionine