Radioimmunotherapy for first-line and relapse treatment of aggressive B-cell non-Hodgkin lymphoma: an analysis of 215 patients registered in the international RIT-Network.

PURPOSE: Very few reliable clinical data about the use of radioimmunotherapy in aggressive B-cell lymphoma exist.
METHODS: Patients with aggressive B-cell lymphoma registered in the international RIT-Network were analysed with regard to prior treatment, response and side effects. The RIT-Network is a web-based registry that collects observational data from radioimmunotherapy-treated patients with malignant lymphoma across 13 countries.
RESULTS: This analysis included 215 with aggressive B-cell lymphoma out of 232 patients registered in the RIT-Network. Histological subtypes were as follows: 190 diffuse large B-cell, 15 primary mediastinal, 9 anaplastic large cell, and 1 intravascular lymphoma. The median age of the patients was 62 years (range 17 - 88), with 27% above the age of 70 years. Radioimmunotherapy was mainly used as consolidation after first-line or second-line chemotherapy (56.1%), as part of third-line to eighth-line therapy for relapse (16.4%), and in refractory disease (12.2%). Grade IV neutropenia and thrombopenia and grade III anaemia were observed. The median time to recovery of blood count was 81 days (range 0 - 600 days). The overall response rate was 63.3%. The complete response rate was 76.4 % in patients treated as part of first-line therapy, and 44.3% in patients with relapse. Mean overall survival in first-line therapy patients was 32.7 months and 14.0 months in patients with relapse or refractory disease, respectively.
CONCLUSION: Most patients with aggressive B-cell lymphoma in the RIT-Network received radioimmunotherapy as consolidation after first-line therapy with excellent complete remission and overall survival rates compared to published data. In relapsed aggressive B-cell lymphoma, radioimmunotherapy is a safe and feasible treatment leading to satisfactory response rates with acceptable toxicity.