. Median, 5 months Control (n = 97): Median, 6.2 months Control (n = 109): Median, 29.5 months Two-sided log-rank P <

. Median, 9 months Declaration and the Disclosures of Potential Conflicts of Interest section in Information for Contributors. Employment or Leadership Position, ) Consultant or Advisory Role

A. Hagenbeek, . Bayer-schering, and . Pharma, Roche International (C) Stock Ownership: None Honoraria: Franck Morschhauser, Bayer Schering Pharma; Achiel Van Hoof, Bayer Schering Pharma

G. Salles, R. Bayer-schering-pharma, . Hagenbeek, . Bayer-schering-pharma, P. C. Vitolo et al., None Other Remuneration: None AUTHOR CONTRIBUTIONS Conception and design: Franck Morschhauser Anton Hagenbeek Administrative support: Marinus H.J. van Oers Provision of study materials or patients: Franck Morschhauser Anton Hagenbeek Collection and assembly of data: Franck Morschhauser Ama Rohatiner Data analysis and interpretation: Franck Morschhauser All rights reserved, 2008.

J. Radford, U. Vitolo, H. J. Marinus, W. Van-oers, J. Van-putten et al., Anton Hagenbeek Final approval of manuscript Anton Hagenbeek Lymphomes de l'Adulte (GELA) 131I- tositumomab therapy as initial treatment for follicular lymphoma EANM procedure guideline for radio-immunotherapy for B-cell lymphoma with 90Y-radiolabelled ibritumomab tiuxetan (Zevalin) al: Ibritumomab tiuxetan radioimmunotherapy for patients with relapsed or refractory non-Hodgkin lymphoma and mild thrombocytopenia: A phase II multicenter trial, Blood N Engl J Med Tennvall J Eur J Nucl Med Mol Imaging Blood, vol.14, issue.99, pp.2540-2544441, 2002.

T. Witzig, I. Flinn, and L. Gordon, B-Cell Non-Hodgkin's Lymphoma, Journal of Clinical Oncology, vol.17, issue.12, pp.3793-38033262, 2002.
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M. Czuczman, C. Emmanouilides, and T. Witzig, Multivariate analysis of prognostic factors correlated with response to 90Y-ibritumomab tiuxetan (Zevalin) radioimmunohterapy for non-Hodgkin's lymphoma Safety and efficacy of yttrium-90 ibritumomab tiuxetan in older patients with non-Hodgkin's lymphoma The Non-Hodgkin's Lymphoma Classification Project: Effect of age on the characteristics and clinical behavior of non-Hodgkin's lymphoma patients Thieblemont C, Coiffier B: Lymphoma in older patients, Health Organization classification of neoplastic diseases of the hematopoietic and lymphoid tissues: Report of the Clinical Advisory Committee meeting? Airlie House Harris NL: Principles of the revised, pp.629-636684, 1062.

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DOI : 10.1200/JCO.1999.17.4.1244

T. Witzig, C. White, and L. Gordon, Safety of yttrium-90 ibritumomab tiuxetan radioimmunotherapy for relapsed low-grade, follicular, or transformed non-Hodgkin's lymphoma Results of a national consensus workshop: Therapeutic algorithm in patients with follicular lymphoma?Role of radioimmunotherapy, al: Consensus conference: Implementing treatment recommendations on yttrium-90 immunotherapy in clinical practice?Report of a European workshop, pp.1263-127081, 2005.

H. Hochster, E. Weller, and R. Gascoyne, Maintenance rituximab after CVP results in superior clinical outcome in advanced follicular lymphoma (FL): Results of the E1496 phase III trial from the Eastern Cooperative Oncology Group and the Cancer and Leukemia Group B, Eur J Cancer Blood, vol.44106, issue.106, pp.366-373, 2005.

?. Morschhauser, All rights reserved, American Society of Clinical Oncology JOURNAL OF CLINICAL ONCOLOGY Copyright ©, vol.8, 2008.

G. E. Verhoef, S. Stroobants, ;. F. Leuven, I. Offner, . Goethals et al., Acknowledgment We thank all of the patients who participated in the study and the contributions of the investigators from all of the following First-Line Indolent Trial study sites: Belgium

:. M. Switzerland, T. Fey, . Krause, ;. T. Bern, B. Cerny et al., The HOVON Data Center/Rotterdam for registration and randomization. Independent data reviewers Appendix 0