Prognostic Value of FDG PET/CT before Allogeneic and Autologous Stem Cell Transplantation for Aggressive Lymphoma

Purpose: To determine the prognostic value of performing fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) before allogeneic and autologous stem cell transplantation (SCT) in patients with aggressive lymphoma. Materials and Methods: A HIPAA-compliant retrospective review was performed under institutional review board waiver. Patients with aggressive lymphoma underwent allogeneic or autologous SCT between January 2005 and December 2010. FDG PET/CT was performed within the 3 months prior to transplantation. PET/CT images were evaluated for lesions with FDG avidity greater than that of the background liver. The relationship between pretransplantation PET and progression-free survival (PFS), disease-specific survival (DSS), and overall survival (OS) was assessed with Kaplan-Meier curves and a corresponding log-rank test for categorical variables and Cox regression for continuous variables. Results: A total of 175 patients were identified, of whom 73 underwent FDG PET/CT before allogeneic SCT and 102 underwent FDG PET/CT before autologous SCT. Before allogeneic SCT, 23 of 73 patients (32%) had FDG-avid lesions, and before autologous SCT, 11 of 102 patients (11%) had FDG-avid lesions. For allogeneic SCT, the 2-year PFS estimate was 68% (95% confidence interval [CI]: 56%, 82%) in patients without FDG-avid lesions, but only 35% (95% CI: 20%, 61%) for patients with FDG-avid lesions (P = .014). For autologous SCT, the 2-year PFS was 72% (95% CI: 64%, 82%) in patients without FDG-avid lesions, but only 18% (95% CI: 5%, 64%) for patients with FDG-avid lesions (P < .0001). Similar differences were seen in OS and DSS. The risk for posttransplantation recurrence correlated with higher lesional maximum standardized uptake values: for PFS, P < .0001 to P = .01; for DSS, P < .0001 to P = .002; and for OS, P < .0001 to P = .015. Conclusion: Performing FDG PET/CT before SCT in patients with aggressive lymphoma has prognostic value. For patients with aggressive lymphomas, the presence of FDG-avid lesions at PET/CT performed before allogeneic and autologous SCT indicates a lower likelihood of SCT success. (C) RSNA, 2015