PET-derived tumor metrics predict DLBCL response and progression-free survival.

[18F] fluorodeoxyglucose (FDG) - positron emission tomography (PET)/computed tomography (CT) is used to stage and assess response in diffuse large B-cell lymphoma (DLBCL), though the prognostic value of tumor metrics calculated from interim scans remains unsolved. We investigated the predictive value of interim and end-of-treatment (EOT) metabolic tumor volume (MTV), and total lesion glycolysis (TLG) on progression-free survival (PFS) at 24 months in patients with DLBCL treated with rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP). Controlling for pretreatment MTV, a positive interim MTV was highly correlated with (0.86) and a significant predictor of a positive EOT MTV (p = .03). Interim MTV > 0 (HR 5.51, CI 1.13, 26.79) and EOT MTV > 4.68 (HR 10.75, CI 1.31, 105.48) were significant predictors of PFS24. Our data show PET-derived metrics of pretreatment and interim MTV offer significant predictive value for EOT response and PFS, and can guide future response-adapted treatment approaches for DLBCL patients that build on the R-CHOP backbone.