Deauville Scores 4 or 5 Assessed by Fluorine-18 Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Early Post-Allotransplant Is Highly Predictive of Relapse in Lymphoma Patients

International audienceThe impact of early fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET-CT) status on survival after allogeneic transplantation for lymphoma is poorly reported. This retrospective study included all adult Hodgkin lymphoma (HL) or non-Hodgkin lymphoma(NHL) patients (>18 years old) who benefited from FDG PET-CT before (within 1 month) and/or early (+3 months and within +6 to 9 months) after allogeneic stem cell transplantation in our institution between 2005 and 2015 and who were still without documented progression or relapse at the time of the FDG PET-CT. All FDG PET-CT were reviewed by a nuclear medicine expert in hematology and restaged according to the Deauville scale. FDG-PET CT was considered positive when the uptake was higher than liver background (Deauville score 4). The primary objective was to study the impact of pre-and post-transplant FDG PET-CT on lymphoma-free survival (LFS) and overall survival (OS). Inclusion criteria were fulfilled for 103 patients (69 men; median age, 51.6 years old; range, 22 to 67). Diagnoses were high-grade NHL (n = 47), low-grade NHL (n = 6), T cell lymphoma (n = 34), and HL (n = 16). More than half of the patients were in complete remission at the time of transplant (n = 56). A reduced-intensity conditioning regimen was applied in most cases (n = 90). With a median follow-up of 49.5 months (range, 6 to 140.5) for alive patients, median 3-year OS and LFS were, respectively, 81% (range, 71% to 87%) and 65% (range, 54% to 74%) for the entire cohort. In multivariate analysis, positive FDG PET-CT at 3 months was the strongest independent factor significantly associated with poorer LFS (hazard ratio, 9.22; 95% confidence interval, 1.88 to 645.2; P = .006). FDG PET-CT positivity at 3 months appears to be highly predictive of LFS in patients after allogeneic transplantation and may help to guide strategies to prevent relapse. These results need to be validated prospectively