PT - JOURNAL ARTICLE AU - Anne-Ségolène Cottereau AU - Sebastien Hapdey AU - Loic Chartier AU - Romain Modzelewski AU - Olivier Casasnovas AU - Emmanuel Itti AU - Herve Tilly AU - Pierre Vera AU - Michel A. Meignan AU - Stéphanie Becker TI - Baseline Total Metabolic Tumor Volume Measured with Fixed or Different Adaptive Thresholding Methods Equally Predicts Outcome in Peripheral T Cell Lymphoma AID - 10.2967/jnumed.116.180406 DP - 2017 Feb 01 TA - Journal of Nuclear Medicine PG - 276--281 VI - 58 IP - 2 4099 - http://jnm.snmjournals.org/content/58/2/276.short 4100 - http://jnm.snmjournals.org/content/58/2/276.full SO - J Nucl Med2017 Feb 01; 58 AB - 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 on 18F-FDG PET/CT with adaptive thresholding methods with TMTV measured with a fixed 41% SUVmax threshold method. Methods: 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% SUVmax threshold 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 SUVmax. The TMTV values obtained with each adaptive method were compared with those obtained with the 41% SUVmax method. Their respective prognostic impacts on outcome prediction were compared using receiver-operating-characteristic (ROC) curve analysis and Kaplan–Meier survival curves. Results: The median value of TMTV41%, TMTVDa, TMTVNs, TMTVFit, and TMTVBl were, 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). Conclusion: 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.