Baseline and interim PET‐based outcome prediction in peripheral T‐cell lymphoma: A subgroup analysis of the PETAL trial
Christine Hanoun, Jan Rekowski, Stefan Müller, Bernd Hertenstein, Christiane Franzius, Arnold Ganser, Frank M. Bengel, Frank Kroschinsky, Jörg Kotzerke, Paul La Rosée, Martin Freesmeyer, Heinz‐Gert Hoeffkes, A. Hertel, Dirk Behringer, Rolf M. Mesters, Matthias Weckesser, Stefan Mahlmann, Uwe Haberkorn, Uwe M. Martens, Gabriele Prange‐Krex, Winfried Brenner, Aristoteles Giagounidis, Regina Moeller, Volker Runde, Matthias Sandmann, Hubertus Hautzel, Stefan Wilop, Thomas Krohn, Heinz Dürk, Michael Heike, Ferras Alashkar, Marcus Brinkmann, Guido Trenn, Dietmar Wacker, C. Kreisel-Büstgens, Helga Bernhard, Gerhard Heil, Rolf Larisch, Lars Kurch, Karl‐Heinz Jöckel, Dieter Hoelzer, Wolfgang Hiddemann, Ronald Boellaard, Ulrich Dührsen, Andreas Hüttmann
Abstract
Abstract The prospective randomized Positron Emission Tomography (PET)‐Guided Therapy of Aggressive Non‐Hodgkin Lymphomas (PETAL) trial was designed to test the ability of interim PET (iPET) to direct therapy. As reported previously, outcome remained unaffected by iPET‐based treatment changes. In this subgroup analysis, we studied the prognostic value of baseline total metabolic tumor volume (TMTV) and iPET response in 76 patients with T‐cell lymphoma. TMTV was measured using the 41% maximum standardized uptake value (SUV 41max ) and SUV 4 thresholding methods. Interim PET was performed after two treatment cycles and evaluated using the ΔSUV max approach and the Deauville scale. Because of significant differences in outcome, patients with anaplastic lymphoma kinase (ALK)‐positive lymphoma were analyzed separately from patients with ALK‐negative lymphoma. In the latter, TMTV was statistically significantly correlated with progression‐free survival, with thresholds best dichotomizing the population, of 232 cm 3 using SUV 41max and 460 cm 3 using SUV 4 . For iPET response, the respective thresholds were 46.9% SUV max reduction and Deauville score 1‐4 vs 5. The proportion of poor prognosis patients was 46% and 29% for TMTV by SUV 41max and SUV 4 , and 29% and 25% for iPET response by ΔSUV max and Deauville, respectively. At diagnosis, the hazard ratio (95% confidence interval) for poor prognosis vs good prognosis patients according to TMTV was 2.291 (1.135‐4.624) for SUV 41max and 3.206 (1.524‐6.743) for SUV 4 . At iPET, it was 3.910 (1.891‐8.087) for ΔSUV max and 4.371 (2.079‐9.187) for Deauville. On multivariable analysis, only TMTV and iPET response independently predicted survival. Patients with high baseline TMTV and poor iPET response (22% of the population) invariably progressed or died within the first year (hazard ratio, 9.031 [3.651‐22.336]). Due to small numbers and events, PET did not predict survival in ALK‐positive lymphoma. Baseline TMTV and iPET response are promising tools to select patients with ALK‐negative T‐cell lymphoma for early allogeneic transplantation or innovative therapies.