cells), or the immunomodulating medication, lenalidomide. While it is too soon to judge the long-term results of the latter regimens, the regimens have shown similar results when analyzed based on poor treatment responses (~10-20% poor responses). Bendamustine with rituximab may be preferable to R-CHOP or R-CVP for treating low-grade (i.e. Grades 1, 2, and possibly 3A) FL; R-CHOP may be preferred in FL that has high-risk characteristics (e.g. high levels of Beta-2 macroglobulin or bone marrow involvement). The combination of lenalidomide with rituximab has shown good potential in treating indolent cases of FL. Studies indicate that maintenance therapy with rituximab following successful induction therapy prolongs progression-free survival; for example one study found progression-free survival after 6 years of treatment was 59.2% in patients treated with rituximab maintenance and 42.7% without this maintenance; however, overall survival at 6 years was similar in the two groups, 87.4% and 88.7%, respectively. Another study found that prolonged maintenance with rituximab did not have any benefits over an eight-month maintenance period. Finally, surgery and radiation are additional therapies that can be used to relieve symptoms caused by bulky t-FL disease or to treat lesions in patients who cannot withstand other types of treatment. Transformed follicular lymphoma Early studies on treating t-FL with various purely chemotherapy regimens gave poor results with median overall survival times of 1–2 years. However, the addition of rituximab to the regimens such as CVP and CHOP as part of induction and maintenance therapies (i.e. R-CVP and R-CHOP) greatly improved overall 5 year survival to rates of 73%. The R-CHOP regimen is a good option for treating such cases. However, these regimens need not be started in people with FL who are asymptomatic and have low tumor burdens: the outcomes in such patients show no difference between early versus delayed treatment. Some recent studies found that the use of rituximab in combination with bendamustine (i.e. the RB regimen) provided better results than R-CHOP: progression-free survival times in one study were 69.5 months for RB and 31.2 months for R-CHOP. Similar results were obtained when RB was compared to R-CVP. These studies also found no overall survival time benefit between the RB and R-CHOP regimens. Other recently examined regimens include 1) the use of obinutuzumab instead of rituximab in the R-CHOP and R-CVP regiments to attain progression-free survival rates at 3 years of 80% for the obinutuzumab-chemotherapy regimen versus 73% for the rituximab-chemotherapy