Abstract 1799

18F-fluoro-2-dexoy-D-glucose-positron emission tomography (FDG-PET)/computerized tomography (CT) has been used for staging and monitoring responses to treatment in patients with diffuse large B cell lymphoma (DLBCL). The sequential interim PET/CT was prospectively investigated to determine whether it provided additional prognostic information and could be a positive predictable value within patients with the same international prognostic index (IPI) after the use of rituximab in DLBCL.

Patients and methods:

One hundred and sixty-one patients with newly diagnosed DLBCL were enrolled between August 2004 and December 2009 at a single institution. The assessment of the PET/CT was performed at the time of diagnosis and mid-treatment of R-CHOP chemotherapy. The clinical stage and response of the patients were assessed according to revised response criteria for aggressive lymphomas (Cheson, J Clin Oncol, 2007). The positivity of interim PET/CT was determined based on the semi-quantitative assessment of the maximal standardized uptake value (SUVmax cut-off value of 3.0).


Sixty-seven patients (41.6%) presented in advanced stage disease and 27 (16.8%) had bulky lesions. At diagnosis, 53 patients (32.9%) were classified as high/high-intermediate risk by the IPI and two patients could not check the interim response due to treatment-related mortality (TRM). Forty-three patients (26.7%) continued to have positive metabolic uptakes with a significantly high relapse rate (62.8%) compared to the patients with a negative interim PET/CT (12.1%) (P<0.01). After a median follow-up of 30.8 months, the positivity of interim PET/CT was found to be a prognostic factor for both OS and PFS, with a hazard ratio of 4.07 (2.62 – 6.32) and 5.46 (3.49 – 8.52), respectively. In the low-risk IPI group, the 3-year OS and PFS rate was significantly different in the patients with positive (53.3 and 52.5%) and negative (93.8 and 88.3%) interim PET/CT, respectively (P<0.01). These significant prognostic differences of interim PET/CT responses were consistent with the results of the patients with high-risk IPI group (P< 0.01).


Interim PET/CT scanning had a significant predictive value for disease progression and survival of DLBCL in post-rituximab treatment; it might be the single most important determinant of clinical outcome in patients with the same IPI risk.


No relevant conflicts of interest to declare.

Author notes


Asterisk with author names denotes non-ASH members.