In 2008, we reported favorable 5-year outcomes of nonmyeloablative allogeneic stem cell transplantation after fludara-bine, cyclophosphamide, rituximab (FCR) conditioning for relapsed and chemosen-sitive follicular lymphoma. However, innovative strategies were still needed to treat patients with chemorefractory disease. We therefore subsequently performed a trial in which Y-ibritumomab tiuxetan (0.4 mCi/kg) was added to the fludara-bine, cyclophosphamide conditioning regimen (90YFC). Here, we report updated results of the FCR trial and outcomes after YPC. For the FCR group (N = 47), since the last update, one patient developed recurrent disease. With a median follow-up of 107 months (range, 72-142 months), the 11-year overall survival and progression-free survival rates were 78%, and 72%, respectively. For the 90YFC group (N = 26), more patients had chemorefractory disease than did those in the FCR group (38% and 0%, P < .001). With a median follow-up of 33 months (range,17-94 months), the 3-year progression-free survival rates for patients with chemorefractory and chemo-sensitive disease were 80% and 87%, respectively (P = .7). The low frequency of relapse observed after a long follow-up interval of 9 years in the FCR group suggests that these patients are cured of their disease. The addition of Y to the conditioning regimen appears to be effective in patients with chemorefractory disease. [ABSTRACT FROM AUTHOR]