Radioimmunotherapy with 131I-Rituximab in a Patient with Diffuse Large B-Cell Lymphoma Relapsed After Treatment with 90Y-Ibritumomab Tiuxetan

We report a case that demonstrates the efficacy of radioimmunotherapy (RIT) with radioiodinated rituximab (131I-rituximab) for relapsed diffuse large B-cell lymphoma (DLBCL). A 79-year-old male patient with DLBCL initially achieved a complete response (CR) after six cycles of RCHOP (rituximab, cyclophosphamide, doxorubicin, vincristine and prednisone) therapy. However, the lymphoma relapsed 20 months later. Although the patient had achieved a second and a third CR after two cycles of 90Y-ibritumomab tiuxetan, he experienced a third relapse approximately 3 years later. Between March and June 2011, the patient received three cycles of 131I-rituximab. Although he had achieved partial response after the second cycle, the disease progressed after the third cycle, and the total progression. Free survival was thus 5 months. The patient suffered only relatively mild toxicity (grade 1 thrombocytopenia) during treatment. RIT with 131I-rituximab is therefore potentially effective in patients with relapsed DLBCL, even after the failure of 90Y-ibritumomab tiuxetan therapy