RT Journal Article SR Electronic T1 18F-FDG PET improves baseline clinical predictors of response in diffuse large B-cell lymphoma: The HOVON-84 study JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP jnumed.121.262205 DO 10.2967/jnumed.121.262205 A1 Coreline N. Burggraaff A1 Jakoba J. Eertink A1 Pieternella J. Lugtenburg A1 Otto S. Hoekstra A1 Anne I.J. Arens A1 Bart de Keizer A1 Martijn W. Heymans A1 Bronno van der Holt A1 Sanne E. Wiegers A1 Simone Pieplenbosch A1 Ronald Boellaard A1 Henrica C.W. de Vet A1 Josée M. Zijlstra YR 2021 UL http://jnm.snmjournals.org/content/early/2021/10/21/jnumed.121.262205.abstract AB We aimed to determine the added value of baseline metabolic tumor volume (MTV) and interim positron emission tomography (I-PET) to age-adjusted international prognostic index (aaIPI) to predict 2-year progression-free survival (PFS) in diffuse large B-cell lymphoma (DLBCL). Secondary objectives were to investigate optimal I-PET response criteria (using Deauville score (DS) - or quantitative change in maximum Standardized Uptake Value (ΔSUVmax) between baseline and I-PET). Methods: Observational I-PET scans were performed after four cycles R(R)-CHOP14 (I-PET4) in the HOVON-84 randomized clinical trial (EudraCT 2006-005174-42), and centrally reviewed using DS (cut-off 4-5). Additionally, ΔSUVmax (prespecified cut-off 70%) and baseline MTV were measured. Multivariable hazard ratios (HR), positive (PPV), and negative predictive values (NPV) were obtained for 2-year PFS. Results: 513 I-PET4 scans were reviewed according to DS, and ΔSUVmax and baseline MTV were available for 367 and 296 patients. NPV of I-PET ranged between 82% and 86% for all PET response criteria. Univariate HR and PPV were optimal for ΔSUVmax (4·8 and 53%, respectively) compared to DS (3·1 and 38%, respectively). AaIPI and ΔSUVmax independently predicted 2-year PFS (HRs 3·2 and 5·0, respectively); adding MTV slightly improved this. Low/low-intermediate aaIPI combined with ΔSUVmax>70% (37% of patients) yielded a NPV of 93%, and the combination of high-intermediate/high aaIPI and ΔSUVmax≤70% a PPV of 65%. Conclusion: In this DLBCL study, I-PET after four cycles R(R)-CHOP14 added predictive value to aaIPI for 2-year PFS, and both were independent response biomarkers in a multivariable Cox model. We externally validated that ΔSUVmax outperformed Deauville score in 2-year PFS prediction.