SUVmax reduction improves early prognosis value of interim positron emission tomography scans in diffuse large B-cell lymphoma

The prognostic value of interim positron emission tomography (PET) interpreted according to visual criteria is a matter of debate in diffuse large B-cell lymphoma (DLBCL). Maximal standardized uptake value reduction (Delta SUVmax) may better predict outcome. To compare the prognostic value of both methods, we analyzed PET done at baseline (PET0) and after 2 (PET2) and 4 (PET4) cycles in 85 patients with high-risk DLBCL enrolled on a prospective multicenter trial. All images were centrally reviewed and interpreted visually according to the International Harmonization Project criteria and by computing Delta SUVmax between PET0 and PET2 (Delta SUVmaxPET0-2) or PET4 (Delta SUVmaxPET0-4). Optimal cutoff to predict progression or death was 66% for Delta SUVmaxPET0-2 and 70% for Delta SUVmaxPET0-4. Outcomes did not differ significantly whether PET2 and PET4 were visually positive or negative. Inversely, Delta SUVmaxPET0-2 analysis (> 66% vs <= 66%) identified patients with significantly different 2-year progression-free survival (77% vs 57%; P = .0282) and overall survival (93% vs 60%; P < .0001). Delta SUVmaxPET0-4 analysis (> 70% vs <= 70%) seemed even more predictive for 2-year progression-free survival (83 vs 40%; P < .0001) and overall survival (94% vs 50%; P < .0001). Delta SUVmax analysis of sequential interim PET is feasible for high-risk DLBCL and better predicts outcome than visual analysis. The trial was registered at http://clinicaltrials.gov as NCT00498043. (Blood. 2011;118(1):37-43)