Fludarabine,Cyclophosphamide and Rituximab Followed by Zevalin for Non-Follicular Indolent Lymphomas.

Test medication: * Yttrium-90 (90Y) ibritumomab tiuxetan 0.4 mCi/kg is delivered to patient achieving at least a partial remission (PR) after chemotherapy as a single dose for patients with baseline platelet counts\>150x10\^9/L or 0.3 mCi/kg for patients with baseline platelet counts of 100 to 149x10\^9/L. Rituximab 250mg/sqm is given prior to therapeutic radiolabeled antibodies. * Standard dose chemotherapy consisting of cyclophosphamide, fludarabine and rituximab given every 28 days up to the best response (maximum 6 courses). * A prophylaxis for pneumocystis carinii as well as for herpes zoster are needed during treatment. Main parameters of activity: activity of Yttrium-90 (90Y) ibritumomab tiuxetan after cyclophosphamide, fludarabine and rituximab combination.