Jeon YW, Park KS, Min GJ, et al. - In order to determine the prognostic utility of ^18F-fluorodeoxyglucose positron emission tomography (^18FF-FDG PET) for mantle cell lymphoma (MCL), researchers performed retrospective evaluation of the correlations of interim PET (iPET) and end-of-treatment PET (ePET) response with survival outcomes in advanced MCL patients. They included 89 advanced MCL patients who had received frontline R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisolone) in this work. Outcomes revealed a strong association of iPET positivity with inferior 5-year overall survival (OS) and poor 5-year progression-free survival (PFS). They observed more favourable OS and PFS in the order early metabolic responder (iPET^neg → ePET^neg), delayed responder (iPET^pos → ePET^neg), loss-metabolic responder (iPET^neg → ePET^pos), and never-metabolic responder (iPET^pos → ePETpos). They observed more favorable OS in the autologous hematopoietic stem cell transplantation (auto-HSCT)-fit subgroup in the order early metabolic responders, delayed metabolic responders, and non-metabolic responders, with a marginal trend toward statistical significance, and PFS was significantly superior in early metabolic responders. In a group that was ineligible for auto-HSCT, early metabolic responders exhibited significantly superior OS and PFS. Results thereby support the prognostic value of iPET and its independent predictive value for survival in MCL patients receiving frontline R-CHOP.