title: Baseline Total Metabolic Tumor Volume Measured with Fixed or Different Adaptive Thresholding Methods Equally Predicts Outcome in Peripheral T Cell Lymphoma.
abstract: The purpose of this study was to compare in a large series of peripheral T cell lymphoma, as a model of diffuse disease, the prognostic value of baseline total metabolic tumor volume (TMTV) measured on18F-FDG PET/CT with adaptive thresholding methods with TMTV measured with a fixed 41% SUVmaxthreshold method.
  
  
  
  One hundred six patients with peripheral T cell lymphoma, staged with PET/CT, were enrolled from 5 Lymphoma Study Association centers. In this series, TMTV computed with the 41% SUVmaxthreshold is a strong predictor of outcome. On a dedicated workstation, we measured the TMTV with 4 adaptive thresholding methods based on characteristic image parameters: Daisne (Da) modified, based on signal-to-background ratio; Nestle (Ns), based on tumor and background intensities; Fit, including a 3-dimensional geometric model based on spatial resolution (Fit); and Black (Bl), based on mean SUVmaxThe TMTV values obtained with each adaptive method were compared with those obtained with the 41% SUVmaxmethod. Their respective prognostic impacts on outcome prediction were compared using receiver-operating-characteristic (ROC) curve analysis and Kaplan-Meier survival curves.
  
  
  
  The median value of TMTV41%, TMTVDa, TMTVNs, TMTVFit, and TMTVBlwere, respectively, 231 cm3(range, 5-3,824), 175 cm3(range, 8-3,510), 198 cm3(range, 3-3,934), 175 cm3(range, 8-3,512), and 333 cm3(range, 3-5,113). The intraclass correlation coefficients were excellent, from 0.972 to 0.988, for TMTVDa, TMTVFit, and TMTVNs, and less good for TMTVBl(0.856). The mean differences obtained from the Bland-Altman plots were 48.5, 47.2, 19.5, and -253.3 cm3, respectively. Except for Black, there was no significant difference within the methods between the ROC curves (P > 0.4) for progression-free survival and overall survival. Survival curves with the ROC optimal cutoff for each method separated the same groups of low-risk (volume ≤ cutoff) from high-risk patients (volume > cutoff), with similar 2-y progression-free survival (range, 66%-72% vs. 26%-29%; hazard ratio, 3.7-4.1) and 2-y overall survival (79%-83% vs. 50%-53%; hazard ratio, 3.0-3.5).
  
  
  
  The prognostic value of TMTV remained quite similar whatever the methods, adaptive or 41% SUVmax, supporting its use as a strong prognosticator in lymphoma. However, for implementation of TMTV in clinical trials 1 single method easily applicable in a multicentric PET review must be selected and kept all along the trial.
authors.affiliation: Nuclear Medicine Department, Hôpital Henri Mondor, University Paris-Est Créteil, Créteil, France annesegolene.cottereau@aphp.fr.
authors.forename: Anne-Ségolène
authors.initials: AS
authors.lastname: Cottereau
authors.affiliation: Nuclear Medicine Department, Henri Becquerel Cancer Center and Rouen University Hospital, Rouen, France.|QuantIF-LITIS (EA [Equipe d'Accueil] 4108), Faculty of Medicine, University of Rouen, Rouen, France.
authors.forename: Sebastien
authors.initials: S
authors.lastname: Hapdey
authors.affiliation: Department of Biostatistics (LYSARC), Centre Hospitalier Lyon Sud, Pierre Bénite, France.
authors.forename: Loic
authors.initials: L
authors.lastname: Chartier
authors.affiliation: Nuclear Medicine Department, Henri Becquerel Cancer Center and Rouen University Hospital, Rouen, France.|QuantIF-LITIS (EA [Equipe d'Accueil] 4108), Faculty of Medicine, University of Rouen, Rouen, France.
authors.forename: Romain
authors.initials: R
authors.lastname: Modzelewski
authors.affiliation: Hematology Department, Hopital Le Bocage-CHU Dijon, France; and.
authors.forename: Olivier
authors.initials: O
authors.lastname: Casasnovas
authors.affiliation: Nuclear Medicine Department, Hôpital Henri Mondor, University Paris-Est Créteil, Créteil, France.
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Itti
authors.affiliation: Hematology Department, UMR918, Henri Becquerel Cancer Center and Rouen University Hospital, Rouen, France.
authors.forename: Herve
authors.initials: H
authors.lastname: Tilly
authors.affiliation: Nuclear Medicine Department, Henri Becquerel Cancer Center and Rouen University Hospital, Rouen, France.|QuantIF-LITIS (EA [Equipe d'Accueil] 4108), Faculty of Medicine, University of Rouen, Rouen, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Vera
authors.affiliation: Nuclear Medicine Department, Hôpital Henri Mondor, University Paris-Est Créteil, Créteil, France.
authors.forename: Michel A
authors.initials: MA
authors.lastname: Meignan
authors.affiliation: Nuclear Medicine Department, Henri Becquerel Cancer Center and Rouen University Hospital, Rouen, France.|QuantIF-LITIS (EA [Equipe d'Accueil] 4108), Faculty of Medicine, University of Rouen, Rouen, France.
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Becker
mesh_terms: D003198:Computer Simulation; D005060:Europe / Q000453:epidemiology; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D016399:Lymphoma, T-Cell / Q000378:metabolism / Q000401:mortality* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D015233:Models, Statistical; D009367:Neoplasm Staging; D000072078:Positron Emission Tomography Computed Tomography / Q000379:methods*; D015995:Prevalence; D011379:Prognosis; D016016:Proportional Hazards Models; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012307:Risk Factors; D012680:Sensitivity and Specificity; D016019:Survival Analysis; D047368:Tumor Burden
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: PTCL; adaptive thresholds; lymphoma; metabolic tumor volume