Validation of the ΔSUV<sub>max</sub>for Interim PET Interpretation in Diffuse Large B-Cell Lymphoma on the Basis of the GAINED Clinical Trial
Emmanuel Itti, Paul Blanc‐Durand, Alina Berriolo-Riedinger, Salim Kanoun, Françoise Kraeber‐Bodéré, Michel Meignan, Elodie Gat, Steven Le Gouill, Olivier Casasnovas, Caroline Bodet‐Milin
Abstract
The GAINED phase 3 trial (ClinicalTrials.gov identifier: NCT01659099) evaluated a PET-driven consolidative strategy in patients with diffuse large B-cell lymphoma. In this post hoc analysis, we aimed to compare the prognostic value of the per-protocol PET interpretation criteria (Menton 2011 consensus) with the change in the SUV<sub>max</sub> (ΔSUV<sub>max</sub>) alone. <b>Methods:</b> Real-time central review of <sup>18</sup>F-FDG PET/CT was performed in 581 patients after 2 cycles (PET2) and 4 cycles (PET4) of immunochemotherapy using the Menton 2011 criteria, combining the ΔSUV<sub>max</sub> (cutoffs of 66% and 70% at PET2 and PET4, respectively) and the Deauville scale. In “special cases,” when the baseline SUV<sub>max</sub> was less than 10.0 or the interim residual tumor SUV<sub>max</sub> was greater than 5.0, the Menton 2011 experts’ consensus agreed that the ΔSUV<sub>max</sub> may not be reliable and that the Deauville score is preferable. Prognostic values of Menton 2011 and ΔSUV<sub>max</sub> were evaluated by Kaplan–Meier analyses in terms of progression-free survival (PFS). <b>Results:</b> Seventeen percent of patients at PET2 (100/581) and 8% at PET4 (49/581) had PET-negative results by ΔSUV<sub>max</sub> but were considered to have PET-positive results according to Menton 2011 with residual SUV<sub>max</sub> of greater than 5.0. For the population with PET2-positive results, 2-y PFS was 70% (range, 58%–80%) with ΔSUV<sub>max</sub> alone, whereas the outcome tended to be better for those who were considered to have PET-positive results by Menton 2011, 81% (range, 72%–87%). Conversely, all 10 patients with baseline SUV<sub>max</sub> of less than 10.0 had PET2-positive results by ΔSUV<sub>max</sub> but were considered to have PET2-negative results by Menton 2011. These patients had the same 2-y PFS as patients with PET2-negative/PET4-negative results, indicating that the ΔSUV<sub>max</sub> yielded false-positive results in this situation. <b>Conclusion:</b> We recommend the use of the ΔSUV<sub>max</sub> alone rather than the Menton 2011 criteria for assessing the interim metabolic response in patients with diffuse large B-cell lymphoma, except when the baseline SUV<sub>max</sub> is less than 10.0.