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.