Prognostic value of FDG-PET in patients with mantle cell lymphoma: results from the LyMa-PET Project

This is the authors' abstract. We don't add key points for this paper.

Mantle cell lymphoma (MCL) is an incurable aggressive non-Hodgkin lymphoma (NHL), which accounts for approximately 5% of all NHL. Novel agents and rituximab maintenance therapy (RM) have greatly improved patient outcomes, but most patients still experience recurrent relapses. This highlights the need for riskadapted therapies. The prognostic value of [(18)F]fluorodeoxyglucose positron-emission-tomography (FDG-PET) has already been demonstrated in various lymphoma entities, but its utility in MCL remains unclear. In the LyMa-PET project, we centrally reviewed PET results from patients enrolled in the LyMa trial, a prospective, multicenter, international, randomized phase III trial (NCT00921414) that investigated RM after autologous stem-cell transplantion (ASCT) in young previously untreated MCL patients. Our aim was to investigate the prognostic value of the image-derived FDG-PET quantitative indices. In the LyMa trial, FDG-PET was optional at diagnosis, before ASCT (iPET) and after-ASCT (eotPET), and not used in the decision-making strategy. FDG-PET images were acquired in voluntary centers participating in the LyMa trial, according to the local protocol and following the rules of good practice. FDG-PET data were centrally collected and analyzed on a dedicated workstation (PLANET®Onco-Solution, Dosisoft, France) and evaluated by two experienced readers (CBM and CB) who were blinded to clinical information, treatment arm and follow-up. For the initial staging, a positive FDG-PET signal was defined as an area of increased uptake thought to be lymphoma-related. Different quantitative metrics were extracted from the FDG-PET data set, measured as volume of interest (VOI) covering the entire nodal and extranodal lesions as visualized by increased FDG uptake: