The purpose of the study is to assess in a prospective series of patients with high tumor burden follicular lymphoma treated with R-CHOP, the predictive value of [18F]-FDG PET performed over (after 4 treatments), and at the end of the first-line treatment on progression-free survival at 2 years.

Inclusion Criteria:

• Patients with malignant non-Hodgkin follicular lymphoma (histologic grade 1 to 3 in the WHO classification), histologically confirmed,
• Patients who have not previously been treated for this disease,
• Introducing one of the criteria for high tumor burden,
• Patients aged over 18 and under 80 years,
• Patients whose ECOG condition is ≤ 2,
• Patients whose haematological functions are adequate within 28 days preceding the treatment (Hemoglobin ≥8,0g/dl; Neutrophils ≥1,5e-9/L, Platelets ≥100e-9/L),
• Patient had the PET examination less than a month before the start of chemotherapy.

Exclusion Criteria:

• Patients with lymphoma who have already transformed or been treated for this disease,
• Patients whose lymphoma is stage 3b,
• Patients with impaired central nervous system,
• Patients regularly taking corticosteroids during the 4 weeks preceding the treatment (unless the dose administered is equivalent to ≤20 mg/day prednisone).
• Patients who have undergone major surgery during the 28 days preceding the inclusion,
• Patients with low kidney and/or liver function,
• Patients with HIV + or had an infection with HBV or HCV less than 4 weeks. Patients with hepatitis B serology is positive unless the sign is related to vaccination,
• Patients whose life expectancy ≤ 6 months,
• Patients sensitive or allergic to murine products,
• Patients who participated in another clinical trial during the 30 days preceding the recording,
• Patients with other medical problems or psychological succeptibles interfere with the study,
• Patients under adult supervision.

High Tumor Burden Follicular Lymphoma patients