Prognostic role of baseline 18F-FDG PET/CT metabolic parameters in elderly HL: a two-center experience in 123 patients

Elderly Hodgkin lymphoma (HL) is an aggressive lymphoma subgroup with high 18F-FDG avidity at 18F-FDG-PET/CT but no shared criteria for PET/CT in treatment evaluation and prediction of outcome are available. The aim of our bicentric study was to investigate whether the metabolic baseline PET/CT parameters can predict treatment response and prognosis in elderly HL. We retrospectively included 123 patients who underwent baseline 18F-FDG-PET/CT and end of treatment PET/CT scans. The PET images were analyzed visually and semi-quantitatively by measuring the lesion to liver SUVmax ratio (L-L SUV R), lesion to blood-pool SUVmax ratio (L-BP SUV R), metabolic tumor volume (MTV), and total lesion glycolysis (TLG). Survival curves were plotted according to the Kaplan-Meier method. At a median follow-up of 40 months, the median PFS and OS were 29 and 37 months. L-BP SUV R, L-L SUV R, MTV, and TLG were significantly higher in patients with no complete response compared with complete response group at end of treatment. Moreover, these parameters were demonstrated to be independent prognostic factors for PFS together with tumor stage, while only L-L SUV R and L-BP SUV R for OS. End of treatment PET/CT results using Deauville criteria were significantly correlated with outcome survival. End of treatment PET/CT results (using Deauville criteria) and semiquantitative baseline PET/CT parameters were significantly correlated with response to treatment and long-term outcome.