title: Combination of baseline metabolic tumour volume and early response on PET/CT improves progression-free survival prediction in DLBCL.
abstract: BACKGROUND
  The study objectives were to assess the prognostic value of quantitative PET and to test whether combining baseline metabolic tumour burden with early PET response could improve predictive power in DLBCL.
  
  
  METHODS
  A total of 147 patients with DLBCL underwent FDG-PET/CT scans before and after two cycles of RCHOP. Quantitative parameters including metabolic tumour volume (MTV) and total lesion glycolysis (TLG) were measured, as well as the percentage change in these parameters. Cox regression analysis was used to test the relationship between progression-free survival (PFS) and the study variables. Receiver operator characteristics (ROC) analysis determined the optimal cut-off for quantitative variables, and Kaplan-Meier survival analysis was performed.
  
  
  RESULTS
  The median follow-up was 3.8 years. As MTV and TLG measures correlated strongly, only MTV measures were used for multivariate analysis (MVA). Baseline MTV (MTV-0) was the only statistically significant predictor of PFS on MVA. The optimal cut-off for MTV-0 was 396 cm(3). A model combing MTV-0 and Deauville score (DS) separated the population into three distinct prognostic groups: good (MTV-0 < 400; 5-year PFS > 90 %), intermediate (MTV-0 ≥ 400+ DS1-3; 5-year PFS 58.5 %) and poor (MTV-0 ≥ 400+ DS4-5; 5-year PFS 29.7 %)
  
  
  CONCLUSIONS
  MTV-0 is an important prognostic factor in DLBCL. Combining MTV-0 and early PET/CT response improves the predictive power of interim PET and defines a poor-prognosis group in whom most of the events occur.
authors.affiliation: Department of Clinical Oncology, Guy's and St Thomas' NHS Foundation Trust, Westminster Bridge Road, SE1 7EH, London, UK. george.mikhaeel@gstt.nhs.uk.
authors.forename: N George
authors.initials: NG
authors.lastname: Mikhaeel
authors.affiliation: Department of Clinical Oncology, Guy's and St Thomas' NHS Foundation Trust, Westminster Bridge Road, SE1 7EH, London, UK.
authors.forename: Daniel
authors.initials: D
authors.lastname: Smith
authors.affiliation: PET Imaging Centre at St Thomas' Hospital, Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK.
authors.forename: Joel T
authors.initials: JT
authors.lastname: Dunn
authors.affiliation: PET Imaging Centre at St Thomas' Hospital, Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Phillips
authors.affiliation: Department of Cancer Epidemiology and Population Health, King's College London, London, UK.
authors.forename: Henrik
authors.initials: H
authors.lastname: Møller
authors.affiliation: Department of Haematology, Guy's and St Thomas' NHS Foundation Trust, London, UK.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Fields
authors.affiliation: Department of Haematology, Guy's and St Thomas' NHS Foundation Trust, London, UK.
authors.forename: David
authors.initials: D
authors.lastname: Wrench
authors.affiliation: PET Imaging Centre at St Thomas' Hospital, Division of Imaging Sciences and Biomedical Engineering, King's College London, London, UK.
authors.forename: Sally F
authors.initials: SF
authors.lastname: Barrington
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018572:Disease-Free Survival; D005260:Female; D006019:Glycolysis; D006801:Humans; D016403:Lymphoma, Large B-Cell, Diffuse / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D000072078:Positron Emission Tomography Computed Tomography; D012189:Retrospective Studies; D047368:Tumor Burden; D055815:Young Adult
keywords: Deauville score; Diffuse large B-cell lymphoma; Metabolic tumour volume; Positron emission tomography; Response assessment