After conventional induction treatment with R-CHOP (Rituximab, cyclophosphamide, adriamycin, vincristine and prednisone) the patients are randomized to:

A: Consolidation with one dose of 90Y Ibritumomab tiuxetan (Zevalin®) 0,4 mCi/Kg

B: Maintenance with 375 mg/m2 of Rituximab every 8 weeks during 24 months

The study will evaluate the benefit of consolidation treatment with 90Y Ibritumomab tiuxetan (Zevalin®) or maintenance with rituximab (MabThera®) in terms of progression free survival, after induction with chemotherapy and rituximab in folicular lymphoma patients no treated previously.

The other aims are, evaluate the global survival, event free survival, time until next treatment, response rate after consolidation or maintenance treatment, quality of life, security of two branches and relation cost-efectivity

Inclusion Criteria:

• Folicular Lymphoma CD20-positive, grade 1, 2 or 3a, confirmed in previous 4 months.

• Patients no treated previously.

• Ann Arbor Stage II, III o IV.

• Symptoms or signes wich indicate necesary treatment (GELF criteria):

  • Ganglionar or extraganglionar mass
  • B Symptoms
  • LDH or B2-microglobuline increased
  • 3 ganglionar territory afected (> 3 cm)
  • Esplenomegalia
  • Compresive syndrome
  • Pleural/peritoneal effusion
  • Secondary medular insufiency due to infiltration

• Age> 18 years and <75 years.

• ECOG < 2

• Adecuate hematological function: Hemoglobin > 8,0 g/dl (5,0 mmol/L); RAN >1,5 x 109/L; platelets > 100 x 109/L

• No pregnant women. Women and man should use an appropiate anticonceptive method during the study and one year after

• Informed consent

Exclusion Criteria:

• Transformation in high grade lymphoma
• FL grade 3b.
• Skin or gastro-intestinal primary lymphoma
• History of CNS diseases ( or CNS lymphoma)
• Previous treatment
• Regulary treatment with corticosteroids (permited < 20 mg/day prednisone or equivalent).
• Previous cancer diseases
• Major surgery in 28 days before inclusion in study.
• Creatinine > 2,0 mg/dl (197 mmol/L)
• Bilirubin > 2,0 mg/dl (34 mmol/L), AST (SGOT) > 3 x upper normal limit.
• HIV infection or active infection VHB o VHC < 4 weeks before inclusion.
• Other complicated diseases

Criteria investigador:

• Life expectancy < 6 months.
• Hipersensibility to Ibritumomab tiuxetan, rituximab, other murines proteins or any excipients.
• Treatment in other experimental study in previous 30 days
• Any medical o psicologycal condition that can modify the capacity to give the consent