Prognostic value of interim (18)F-FDG PET/CT in diffuse large B-cell lymphoma.

OBJECTIVE Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease. The prognostic factor currently used is not accurate enough to predict the outcomes of patients with DLBCL. The prognostic significance of interim PET/CT in DLBCL remains controversial. The aim of this study is to determine the predictive value of interim (18)F-FDG PET/CT after first-line treatment in patients with DLBCL. METHODS Thirty-two patients with DLBCL underwent baseline, interim and post-treatment (18)F-FDG PET/CT scans. Imaging results were analyzed for the survival of patients via software SPSS 13.0, retrospectively. RESULTS Thirty-one of the 32 patients were treated with R-CHOP regimen, and interim (18)F-FDG PET/CT of 24 patients was performed after 2 cycles of treatment. After a median follow-up period of 16.7 months, the 2-year progression-free survival (PFS) rates were significantly different between the groups above and below SUV(max) cut-off value of 2.5 (P=0.039). No significant differences were found in the 2-year PFS rates if SUV(max) cut-off values were set as 2.0 and 3.0, respectively (P=0.360; P=0.113). CONCLUSIONS Interim PET/CT could predict the prognosis of DLBCL patients with the SUV(max) cut-off value of 2.5, but more clinical data should be concluded to confirm this conclusion. KEY WORDS Fludeoxyglucose F18; lymphoma; large cell; diffuse; prognosis; standard utility value.