A Randomized Phase II Study Comparing Consolidation With a Single Dose Of 90y Ibritumomab Tiuxetan (Zevalin®) (Z) Vs. Maintenance With Rituximab (R) For Two Years In Patients With Newly Diagnosed Follicular Lymphoma (FL) Responding To R-CHOP. Preliminary Results At 36 Months From Randomization | Publicación