A research study of a new method of visualizing internal organs called 18F-FLT PET/CT that yields better tracking of cancer treatment progress. PET/CT stands for positron emission tomography with low dose computed tomography and has been used for many years. 18F-FLT PET/CT uses a new tracer, fluorothymidine, which is taken up by cells that are actively proliferating or dividing such as cancer cells. We hope to learn whether this tracer is superior to the conventional tracer for monitoring treatment of diffuse large B-cell lymphoma (DLBCL).
-Primary Objective Investigate whether the PPV of FLT-PET/CT is significantly higher than that of FDG-PET/CT by following up patients for at least 24 months post-therapy or until evidence of persistent disease/disease progression. -Secondary Objectives Investigate whether the event free survival (EFS) of patients with FDG-PET/CT-positive and FLT-PET/CT negative scans is not significantly lower than that of patients with concordantly negative FDG-PET/CT and FLT-PET/CT scans and that the NPV or FLT-PET/CT is similar to that of FDG-PET/CT Correlate interim FLT-PET/CT and FDG-PET/CT with the International Prognostic Index (IPI), a well-established predictor of outcome in DLBCL, to determine their independent prognostic value from the IPI